FOR PUBLICATION

   UNITED STATES COURT OF APPEALS
        FOR THE NINTH CIRCUIT

LINDSAY HECOX; JANE DOE, with              No. 20-35813
her next friends Jean Doe and John
Doe,                                      D.C. No. 1:20-cv-
                                            00184-DCN
               Plaintiffs-Appellees,
  v.

BRADLEY LITTLE, in his official              OPINION
capacity as Governor of the State of
Idaho; SHERRI YBARRA, in her
official capacity as the Superintendent
of Public Instruction of the State of
Idaho and as a member of the Idaho
State Board of Education;
INDIVIDUAL MEMBERS OF THE
STATE BOARD OF EDUCATION, in
their official capacities; BOISE
STATE UNIVERSITY; MARLENE
TROMP, in her official capacity as
President of Boise State University;
INDEPENDENT SCHOOL
DISTRICT OF BOISE CITY, # 1;
COBY DENNIS, in his official
capacity as superintendent of the
Independent School District of Boise
2                      HECOX V. LITTLE


City #1; INDIVIDUAL MEMBERS
OF THE BOARD OF TRUSTEES OF
THE INDEPENDENT SCHOOL
DISTRICT OF BOISE CITY, # 1; in
their official capacities; INDIVIDUAL
MEMBERS OF THE IDAHO CODE
COMMISSION, in their official
capacities,

               Defendants-Appellants,
    and

MADISON KENYON; MARY
MARSHALL,

               Intervenors.



LINDSAY HECOX; JANE DOE, with              No. 20-35815
her next friends Jean Doe and John
Doe,                                      D.C. No. 1:20-cv-
                                            00184-DCN
               Plaintiffs-Appellees,
    v.

BRADLEY LITTLE, in his official
capacity as Governor of the State of
Idaho; SHERRI YBARRA, in her
official capacity as the Superintendent
of Public Instruction of the State of
                     HECOX V. LITTLE    3


Idaho and as a member of the Idaho
State Board of Education;
INDIVIDUAL MEMBERS OF THE
STATE BOARD OF EDUCATION, in
their official capacities; BOISE
STATE UNIVERSITY; MARLENE
TROMP, in her official capacity as
President of Boise State University;
INDEPENDENT SCHOOL
DISTRICT OF BOISE CITY, # 1;
COBY DENNIS, in his official
capacity as superintendent of the
Independent School District of Boise
City #1; INDIVIDUAL MEMBERS
OF THE BOARD OF TRUSTEES OF
THE INDEPENDENT SCHOOL
DISTRICT OF BOISE CITY, # 1; in
their official capacities; INDIVIDUAL
MEMBERS OF THE IDAHO CODE
COMMISSION, in their official
capacities,

              Defendants,
 and

MADISON KENYON; MARY
MARSHALL,

              Intervenors-Appellants.
4                          HECOX V. LITTLE


         Appeal from the United States District Court
                   for the District of Idaho
         David C. Nye, Chief District Judge, Presiding

           Argued and Submitted November 22, 2022
                   San Francisco, California

                      Filed August 17, 2023

     Before: Kim McLane Wardlaw, Ronald M. Gould, and
              Morgan Christen, Circuit Judges. *

                   Opinion by Judge Wardlaw;
    Partial Concurrence and Partial Dissent by Judge Christen


                           SUMMARY **


            Equal Protection/Transgender Status

    The panel affirmed the district court’s order
preliminarily enjoining Idaho’s Fairness in Women’s Sports
Act, a categorical ban on the participation of transgender
women and girls in women’s student athletics.



*
  Pursuant to General Order 3.2(h), Judge Christen has been drawn to
replace Judge Kleinfeld in this matter. Judge Christen has reviewed the
briefs and the record, and listened to the recording of the oral argument
in this case.
**
  This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
                        HECOX V. LITTLE                       5


    The Act bars all transgender women and girls from
participating in, or trying out for, public school female sports
teams at every age, from primary school through college,
and at every level of competition, from intramural to elite
teams. It also provides a sex dispute verification process
whereby any individual can “dispute” the sex of any female
student athlete in the state of Idaho and require her to
undergo intrusive medical procedures to verify her sex,
including gynecological exams. Male student athletes in
Idaho are not subject to a similar dispute process.
    The panel held that the district court did not abuse its
discretion when it found, on the record before it, that
plaintiffs were likely to succeed on the merits of their claim
that the Act violates the Equal Protection Clause of the
Fourteenth Amendment.
    Citing United States v. Virginia, 

(1996), and Karnoski v. Trump, 

, 1200–01 (9th
Cir. 2019), the panel stated that a heightened level of
scrutiny applies to laws that discriminate on the basis of
transgender status and sex. The district court did not err in
concluding that heightened scrutiny applied because the Act
discriminates on the basis of transgender status by
categorically excluding transgender women from female
sports and on the basis of sex by subjecting all female
athletes, but not male athletes, to invasive sex verification
procedures to implement that policy.
    Because the Act subjects only women and girls who wish
to participate in public school athletic competitions to an
intrusive sex verification process and categorically bans
transgender women and girls at all levels, regardless of
whether they have gone through puberty or hormone
therapy, from competing on female, women, or girls teams,
6                       HECOX V. LITTLE


and because the State of Idaho failed to adduce any evidence
demonstrating that the Act is substantially related to its
asserted interests in sex equality and opportunity for women
athletes, the panel held that plaintiffs were likely to succeed
on the merits of their equal protection claim.
    Concurring in part and dissenting in part, Judge Christen
wrote that given the categorical sweep of the ban on
transgender students, the medical consensus that circulating
testosterone rather than transgender status is an accurate
proxy for athletic performance, and the unusual and extreme
nature of the Act’s sex verification requirements, the district
court did not abuse its discretion by granting injunctive
relief.
    Disagreeing with the majority in part, Judge Christen
wrote that she read the sex dispute verification provision to
apply to any student, male or female, who participates on
women’s or girls’ athletic teams. Accordingly, it is the team
an athlete chooses to join that dictates whether they are
subject to the statute’s verification process, not the athlete’s
sex. Judge Christen also wrote that the district court’s
injunction lacked specificity as required by Federal Rule of
Civil Procedure 65(d)(1) because it failed, among other
things, to specify whether it was enjoining all provisions of
the Act, or only some of them, or whether it was enjoining
any specific provision of the Act in its entirety or only as
applied to certain classes of individuals. Finally, Judge
Christen stated that the injunction was overbroad to the
extent that it applies to transgender women who are not
receiving gender-affirming hormone therapy.
                      HECOX V. LITTLE                   7


                       COUNSEL

W. Scott Zanzig (argued), Dayton P. Reed, Timothy
Longfield, and Brian V. Church, Deputy Attorneys General;
Lincoln D. Wilson; Steven L. Olsen, Chief of Civil
Litigation Division; Brian Kane, Assistant Chief Deputy;
Lawrence G. Wasden, Attorney General; Boise, Idaho, for
Defendants-Appellants.
Kristen K. Waggoner, John J. Bursch, and Christiana M.
Holcomb, Alliance Defending Freedom, Washington, D.C.;
Bruce D. Skaug and Raul R. Labrador, Skaug Law PC,
Nampa, Idaho; Roger G. Brooks, Alliance Defending
Freedom, Scottsdale, Arizona; Christopher P. Schandevel,
Alliance Defending Freedom, Ashburn, Virginia; Cody S.
Barnett, Alliance Defending Freedom, Lansdowne,
Virginia; for Intervenors-Appellants.
Andrew Barr (argued), Cooley LLP, Broomfield, Colorado;
Chase Strangio and James D. Esseks, American Civil
Liberties Union Foundation, New York, New York; Richard
Eppink and Dina M. Flores-Brewer, American Civil
Liberties Union of Idaho Foundation, Boise, Idaho;
Elizabeth Prelogar, Cooley LLP, Washington, D.C.;
Catherine West, Legal Voice, Seattle, Washington; Kathleen
R. Hartnett, Cooley LLP, San Francisco, California; Selim
Aryn Star, Star Law Office PLLC, Hailey, Idaho; for
Plaintiffs-Appellees.
Lauren R. Adams, Women’s Liberation Front, Washington,
D.C., for Amicus Curiae Women’s Liberation Front.
James A. Campbell, Solicitor General; David T. Bydalek,
Chief Deputy Attorney General; Douglas J. Peterson,
Attorney General of Nebraska; Nebraska Attorney General’s
Office, Lincoln, Nebraska; for Amici Curiae States of
8                     HECOX V. LITTLE


Nebraska, Alabama, Alaska, Arkansas, Indiana, Kansas,
Kentucky, Louisiana, Mississippi, Montana, Oklahoma,
South Carolina, Texas, and West Virginia.
Kara Dansky, Women’s Human Rights Campaign – USA,
Medford, Oregon, for Amicus Curiae Women’s Human
Rights Campaign – USA.
Randall L. Wenger, Independence Law Center, Harrisburg,
Pennsylvania; Gary S. McCaleb, Flagstaff, Arizona; for
Amici Curiae Medical Professionals in Support of
Interveners-Appellants and Urging Reversal.
Thomas E. Chandler, Matthew J. Donnelly, and Elizabeth
Hecker, Attorneys; Alexander V. Maugeri, Deputy Assistant
Attorney General; Eric S. Dreiband, Assistant Attorney
General; United States Department of Justice, Civil Rights
Division, Appellate Section, Washington, D.C.; Candice
Jackson and Farnaz F. Thompson, Deputy General
Counsels; Reed R. Rubinstein, Principal Deputy General
Counsel; United States Department of Education, Office of
the General Counsel, Washington, D.C.; Peter L. Wucetich,
Assistant United States Attorney; Bart M. Davis, United
States Attorney; Boise, Idaho; for Amicus Curiae United
States.
Edward M. Wenger, Tallahassee, Florida, for Amicus Curiae
Sandra Bucha, Linda Blade, Vicki Huber-Rudawsky, Inga
Thompson, Maria Blower, and Rebecca Dussault.
Chris N. Ryder and Gail Hammer, Lincoln LGBTQ+ Rights
Clinic, Spokane, Washington, for Amicus Curiae Lincoln
LGBTQ+ Rights Clinic.
Jessica L. Ellsworth, Kaitlyn A. Golden, Danielle D.
Stempel, Nel-Sylvia Guzman, and Ray Li, Hogan Lovells
US LLP, Washington, D.C.; Fatima G. Graves, Emily
                     HECOX V. LITTLE                   9


Martin, Sunu Chandy, Neena Chaudhry, Shiwali Patel, and
Cassandra Mensah, National Women’s Law Center,
Washington, D.C.; Jon Greenbaum, David Hinojosa, and
Bryanna A. Jenkins, Lawyers’ Committee for Civil Rights
Under Law, Washington, D.C.; for Amici Curiae National
Women’s Law Center, Lawyers’ Committee for Civil Rights
Under Law and 60 Additional Organizations.
Carl S. Charles, Lambda Legal Defense and Education Fund
Inc., Atlanta, Georgia; Paul D. Castillo, Lambda Legal
Defense and Education Fund Inc., Dallas, Texas; Diana
Flynn and Omar Gonzalez-Pagan, Lambda Legal Defense
and Education Fund Inc., New York, New York; Sasha
Buchert, Lambda Legal Defense and Education Fund Inc.,
Washington, D.C.; for Amici Curiae 176 Athletes in
Women’s Sports, The Women’s Sports Foundation, and
Athlete Ally in Support of Plaintiffs-Appellees and
Affirmance.
Jonah M. Knobler, Patterson Belknap Webb & Tyler LLP,
New York, New York, for Amicus Curiae interACT:
Advocates for Intersex Youth.
Jesse R. Loffler, Cozen O’ Connor, for Amici Curiae
Transgender Women Athletes.
Aaron M. Panner, Kellogg Hansen Todd Figel & Frederick
PLLC, Washington, D.C.; Scott B. Wilkens, Wiley Rein
LLP, Washington, D.C.; for Amici Curiae American
Academy of Pediatrics, American Medical Association,
American Psychiatric Association, and 10 Additional
Healthcare Organizations.
Adam R. Tarosky, Seth D. Levy, and Sarah E. Andre, Nixon
Peabody LLP, Los Angeles, California, for Amicus Curiae
Three Former Idaho Attorneys General.
10                    HECOX V. LITTLE


Matthew D. Benedetto, Thomas F. Costello, William Cutler
Pickering, Hale and Dorr LLP, Los Angeles, California;
Adam M. Cambier and Alison Burton, Wilmer Cutler
Pickering, Hale and Dorr LLP, Boston, Massachusetts; for
Amici Curiae Teammates, Coaches, and Allies of
Transgender Athletes.
Angela R. Vicari, Rosalyn Richter, Arnold & Porter Kaye
Scholer LLP, New York, New York; Kirk Jenkins, Arnold
& Porter Kaye Scholer LLP, San Francisco, California; for
Amici Curiae Altria Group Inc., Amalgamated Bank, Asana
Inc., Ben and Jerry’s Homemade Inc., Lush Cosmetics LLC,
Nike Inc., and The Burton Corporation.
Kaliko‘onalani D. Fernandes, Deputy Solicitor General of
Counsel; Kimberly T. Guidry, Solicitor General; Clare E.
Connors, Attorney General of Hawaii; Honolulu, Hawaii;
Linda Fang, Assistant Solicitor General of Counsel; Anisha
S. Dasgupta, Deputy Solicitor General; Barbara D.
Underwood, Solicitor General; Letitia James, Attorney
General, State of New York; New York, New York; Xavier
Becerra, California Attorney General, Sacramento,
California; Philip J. Weiser, Colorado Attorney General,
Denver, Colorado; William Tong, Connecticut Attorney
General, Hartford, Connecticut; Kathleen Jennings,
Delaware Attorney General, Wilmington, Delaware;
Kwame Raoul, Illinois Attorney General, Chicago, Illinois;
Aaron M. Frey, Maine Attorney General, August, Maine;
Brian E. Frosh, Maryland Attorney General, Baltimore,
Maryland; Maura Healey, Commonwealth of Massachusetts
Attorney General, Boston, Massachusetts; Keith Ellison,
Minnesota Attorney General, St. Paul, Minnesota; Aaron D.
Ford, Nevada Attorney General, Carson City, Nevada;
Gurbir S. Grewal, New Jersey Attorney General, Trenton,
New Jersey; Hector Balderas, New Mexico Attorney
                     HECOX V. LITTLE                   11


General, Santa Fe, New Mexico; Joshua E. Stein, North
Carolina Attorney General, Raleigh, North Carolina; Ellen
F. Rosenblum, Oregon Attorney General, Salem, Oregon;
Joshua Shapiro, Commonwealth of Pennsylvania Attorney
General, Philadelphia, Pennsylvania; Peter F. Neronha,
Rhode Island Attorney General, Providence, Rhode Island;
Thomas J. Donovan, Jr., Vermont Attorney General,
Montpelier, Vermont; Mark R. Herring, Commonwealth of
Virginia Attorney General, Richmond, Virginia; Robert W.
Ferguson, Washington Attorney General, Olympia,
Washington; Karl A. Racine, District of Columbia Attorney
General, Washington, D.C.; for Amici Curiae States of New
York, Hawai‘i, California, Colorado, Connecticut,
Delaware, Illinois, Maine, Maryland, Massachusetts,
Minnesota, Nevada, New Jersey, New Mexico, North
Carolina, Oregon, Pennsylvania, Rhode Island, Vermont,
Virginia, and Washington, and the District of Columbia.
Susan B. Manning, Morgan Lewis & Bockius LLP,
Washington, D.C.; for Amici Curiae GLBTQ Legal
Advocates & Defenders and the National Center for Lesbian
Rights.
Abbey J. Hudson, Gibson Dunn & Crutcher LLP, Los
Angeles, California, for Amicus Curiae The Trevor Project
Inc.
12                     HECOX V. LITTLE

OPINION

WARDLAW, Circuit Judge:

     In March 2020, Idaho enacted the Fairness in Women’s
Sports Act, 

-6201⁠–06 (2020) (the “Act”), a
first-of-its-kind categorical ban on the participation of
transgender women and girls in women’s student athletics.
At the time, Idaho had no history of transgender women and
girls participating in competitive student athletics, even
though Idaho’s interscholastic athletics organization allowed
transgender girls to compete on female athletic teams under
certain specified conditions. Elite athletic regulatory bodies,
including the National Collegiate Athletic Association
(NCAA) and the International Olympic Committee (IOC),
also had policies allowing transgender women athletes to
compete if they met certain criteria. The Act, however, bars
all transgender girls and women from participating in, or
even trying out for, public school female sports teams at
every age, from primary school through college, and at every
level of competition, from intramural to elite teams. See

(1)–(2). The Act also provides a sex
dispute verification process whereby any individual can
“dispute” the sex of any female student athlete in the state of
Idaho and require her to undergo intrusive medical
procedures to verify her sex, including gynecological exams.
See 

(3). Male student athletes in
Idaho are not subject to a similar dispute process.
    Today, we decide only the question of whether the
federal district court for the District of Idaho abused its
discretion in August 2020 when it preliminarily enjoined the
Act, holding that it likely violated the Equal Protection
Clause of the Fourteenth Amendment. Because the Act
                         HECOX V. LITTLE                        13


subjects only women and girls who wish to participate in
public school athletic competitions to an intrusive sex
verification process and categorically bans transgender girls
and women at all levels from competing on “female[],
women, or girls” teams, 

(2), and
because the State of Idaho failed to adduce any evidence
demonstrating that the Act is substantially related to its
asserted interests in sex equality and opportunity for women
athletes, we affirm the district court’s grant of preliminary
injunctive relief.
    I. FACTUAL AND PROCEDURAL BACKGROUND
                                A.
    As the district court noted, and as we recognize in this
context, “such seemingly familiar terms as ‘sex and gender’
can be misleading,” Hecox v. Little, 

, 945
(D. Idaho 2020) (quoting Doe ex rel. Doe v. Boyertown Area
Sch. Dist., 

 (3d Cir. 2018)). We therefore
adopt the terminology that has been employed throughout
this case.
    “Gender identity” is “the term used to describe a person’s
sense of being male, female, neither, or some combination
of both.” 1 A person’s “sex” is typically assigned at birth
based on an infant’s external genitalia, though “external
genitalia” do not always align with other sex-related
characteristics, which include “internal reproductive organs,
gender identity, chromosomes, and secondary sex
characteristics.”    A “transgender” individual’s gender
identity does not correspond to their sex assigned at birth,
while a “cisgender” individual’s gender identity corresponds

1
 Joshua D. Safer & Vin Tangpricha, Care of Transgender Persons, 381
N. Eng. J. Med. 2451, 2451 (2019)
14                         HECOX V. LITTLE


with the sex assigned to them at birth. Around two percent
of the population are born “intersex,” which is an umbrella
term for people “born with unique variations in certain
physiological characteristics associated with sex, such as
chromosomes, genitals, internal organs like testes or ovaries,
secondary sex characteristics, or hormone production or
response.” Id. at 946 (internal quotation marks omitted).
    Currently, over 1.6 million adults and youth identify as
transgender in the United States, or roughly 0.6 percent of
Americans who are 13 years old or older. 2 Youth ages 13 to
17 are significantly more likely to identify as transgender,
with the Center for Disease Control (CDC) estimating that
roughly 1.8 percent of high school students identify as
transgender. See Br. of Amici Curiae Am. Acad. of
Pediatrics, et al. (“AAP Br.”) at 10.
    Transgender individuals often experience “gender
dysphoria,” which is defined by the Fifth Edition of the
Diagnostic and Statistics Manual of Mental Disorders
(DSM-5) as a condition where patients experience “[a]
marked incongruence between one’s experienced/expressed
gender and primary and/or secondary sex characteristics”
that “is associated with clinically significant distress or
impairment in social, occupation, or other important areas of
functioning.” 3 For over 30 years, medical professionals
have treated individuals experiencing gender dysphoria
following the protocols laid out in the Standards of Care for


2
 See Jody L. Herman, Andrew R. Flores, Kathryn K. O’Neill, How Many
Adults and Youth Identify as Transgender in the United States?, Williams
Inst. 1 (2022).
3
  See Am. Psychiatric Ass'n, Diagnostic and Statistics Manual of Mental
Disorders 452–53 (5th ed. 2013).
                            HECOX V. LITTLE                              15


the Health of Transsexual, Transgender, and Gender
Nonconforming People (Version 7), which were developed
by the World Professional Association for Transgender
Health (WPATH). AAP Br. at 19.
                                    B.
        On March 16, 2020, Idaho passed House Bill 500
    (“H.B. 500”), a categorical ban against transgender women
    and girls’ participation in any public-school funded
    women’s sport, implemented by subjecting all female
    athletes to an intrusive sex verification process if their
    gender is disputed by anyone. See H.R. 500, 65th Leg., 2d
    Reg. Sess. (Idaho 2020). Although Idaho was the first state
    in the nation to issue such a ban, twenty other states have
    enacted similar—though perhaps not as potentially
    intrusive against all female athletes—restrictions on female
    transgender athletes. 4



4
  Since the Act’s passage, twenty other states have passed laws limiting
the participation of transgender students in women’s athletics. However,
no other state appears to have enacted an enforcement mechanism for
those restrictions like the sex dispute verification process in the Act. See

 (2021); 

 (2022);

 (West 2021); 

(West 2021); 

 (West 2022); Iowa Code
Ann. § 261I.2 (West 2022); H.B. 2238, 2023 Leg. Sess. (Kan. 2023); 

 (West 2022); 

 (2022);

 (West 2021); 

(West 2021); Legis. Assemb. 1489, 68th Legis. Assemb., Reg. Sess.
(N.D. 2023); Legis. Assemb. 1249, 68th Legis. Assemb., Reg. Sess.
(N.D. 2023); 

 (West 2022); 

 (2022); 

 (2022); 

 (2022); 

 (West
2022); Utah Code Ann. § 53g-6-902 (West 2022); 

-25d (West 2021); S. 92, 67th Leg., Gen. Sess. (Wyo. 2023).
16                         HECOX V. LITTLE


    In the United States, high school interscholastic athletics
are generally governed by state interscholastic athletic
associations, such as the Idaho High School Activities
Association (IHSAA). The NCAA sets policies for member
colleges and universities, including Boise State University
(BSU) and other Idaho colleges and universities. Prior to the
Act’s passage, IHSAA policy allowed transgender girls in
K–12 athletics in Idaho to compete on girls’ teams after they
had completed one year of hormone therapy suppressing
testosterone under the care of a physician. At that time,
NCAA policy similarly allowed transgender women
attending member colleges and universities in Idaho (and
elsewhere) to compete on women’s teams after one year of
hormone therapy to suppress testosterone. 5 Idaho itself had
no record of transgender women and girls participating in
competitive women’s sports.
    On February 13, 2020, Representative Barbara Ehardt
introduced H.B. 500 in the Idaho House of Representatives.
At the first hearing on the bill, Ty Jones, Executive Director
of the IHSSA, testified that no student in Idaho had ever
complained about participation in public school sports by
transgender athletes, and no transgender athlete had ever
competed in Idaho under the existing IHSSAA policy.
Representative Ehardt herself acknowledged that she had no


5
  In April 2023, the NCAA updated its policy to require that transgender
student-athletes meet the “sport-specific standard[s] (which may include
testosterone levels, mitigation timelines and other aspects of sport-
governing body policies)” of the national governing body of that sport.
See Press Release, NCAA, Transgender Student-Athlete Participation
Policy                   (April                17,                2023),
https://www.ncaa.org/sports/2022/1/27/transgender-participation-
policy.aspx (last visited May 23, 2023).
                        HECOX V. LITTLE                      17


evidence to date that any person in Idaho had ever disputed
an athlete’s eligibility to play based on that athlete’s gender.
    After the bill passed out of the Idaho House Committee,
Idaho Attorney General Lawrence Wasden warned in a
written opinion letter to the House that H.B. 500 raised
serious constitutional questions due to the legislation’s
disparate treatment of transgender and intersex athletes and
the potential invasion of all female athletes’ privacy inherent
in the sex dispute verification process. Nevertheless, the bill
proceeded to a debate and passed the House floor on
February 26, 2020.
    After passage by the House, H.B. 500 was heard by the
Senate State Affairs Committee and sent to the entire Idaho
Senate on March 10, 2020. On March 11, 2020, the World
Health Organization declared COVID-19 a pandemic and
many states adjourned legislative sessions indefinitely. The
Idaho Senate remained in session, however, and passed H.B.
500 as amended on March 16, 2020. The House concurred
in the Senate amendments on March 18, and the bill was
delivered to Idaho Governor Bradley Little on March 19,
2020.
     As Governor Little considered the bill, critics sharply
contested the legislation’s findings and legality. Professor
Dorianne Lambelet Coleman, whose work on testosterone
and athletics was cited in the legislative findings in support
of the bill, wrote to Governor Little urging him to veto the
bill and explaining that her research was misinterpreted and
misused in the legislative findings. Similarly, five former
Idaho Attorneys General implored Governor Little to veto
18                       HECOX V. LITTLE


the Act, labeling it a “legally infirm statute.” 6 Nonetheless,
Governor Little signed H.B. 500 into law on March 30, 2020,
and it went into effect on July 1, 2020.
                               C.
    In enacting H.B. 500, the legislature made several
findings purportedly based on Professor Coleman’s study,
including “that there are ‘inherent [biological] differences
between men and women,’” 

(1)
(quoting United States v. Virginia (“VMI”), 

 (1996)), and that men have “higher natural levels of
testosterone,” 

 § 33-6202(4), which “have lifelong effects,
including those most important for success in sport,” id.
§ 33-6202(5). Relying on Professor Coleman’s work, the
legislature found that “[t]he benefits that natural testosterone
provides to male athletes is [sic] not diminished through the
use of puberty blockers and cross-sex hormones.” Id. § 33-
6202(11). The legislature also found that “women’s
performances at the high[est] level [of athletics] will never
match those of men.” Id. § 33-6202(9) (quoting Valterie
Thibault et al., Women and Men in Sport Performance: The
Gender Gap Has Not Evolved Since 1983, 9 J. of Sports Sci.
& Med. 214, 219 (2010)). The legislature concluded that
“[h]aving separate sex-specific teams furthers efforts to
promote sex equality” by “providing opportunities for
female athletes to demonstrate their skill, strength, and
athletic abilities, while also providing them with
opportunities to obtain recognition and accolades, college


6
  See also Tony Park et al., 5 Former Idaho Attorneys General Urge
Transgender Bill Veto, Idaho Statesman (Mar. 17, 2020),
https://www.idahostatesman.com/opinion/readers-
opinion/article241267071.html (last visited May 23, 2023).
                       HECOX V. LITTLE                      19


scholarships, and numerous other long-term benefits that
flow from success in athletic endeavors.” Id. § 33-6202(12).
    Three provisions of the Act are most salient to this
appeal. First, the Act provides that “[i]nterscholastic, inter-
collegiate, intramural, or club athletic teams or sports that
are sponsored by a [public school]” should be organized
“based on biological sex.” Id. § 33-6203(1). It specifically
provides that:

       Interscholastic, intercollegiate, intramural, or
       club athletic teams or sports that are
       sponsored by a public primary or secondary
       school, a public institution of higher
       education, or any school or institution whose
       students or teams compete against a public
       school or institution of higher education shall
       be expressly designated as one (1) of the
       following based on biological sex:
           (a) Males, men, or boys;
           (b) Females, women, or girls; or
           (c) Coed or mixed.

Id. The Act then provides that “[a]thletic teams or sports
designated for females, women, or girls shall not be open to
students of the male sex.” Id. at § 33-6203(2) (the
“categorical ban provision”). The Act’s provisions apply to
all levels of competition in Idaho state schools, including
elementary school and club teams, and do not include any
limitation for transgender individuals who wish to
participate on athletic teams designated for men. Moreover,
the provisions apply to students in nonpublic schools “whose
20                     HECOX V. LITTLE


students or teams compete against a public school or
institution of higher education.” Id. at § 33-6203(1).
    Second, the Act creates a “sex verification” process to be
invoked by any individual who wishes to “dispute” a
student’s sex, providing that:

       A dispute regarding a student’s sex shall be
       resolved by the school or institution by
       requesting that the student provide a health
       examination and consent form or other
       statement signed by the student’s personal
       health care provider that shall verify the
       student’s biological sex. The health care
       provider may verify the student’s biological
       sex as part of a routine sports physical
       examination relying only on one (1) or more
       of the following: the student’s reproductive
       anatomy, genetic makeup, or normal
       endogenously produced testosterone levels.

Id. at § 33-6203(3) (the “sex dispute verification provision”).
    And third, the Act creates an enforcement mechanism to
ensure compliance with its provisions by establishing a
private cause of action for any student who is “deprived of
an athletic opportunity or suffers any direct or indirect harm
as a result of a violation of [the Act].” Id. at § 33-6205(1).
                              D.
    On April 15, 2020, Lindsay Hecox (“Lindsay”), a
transgender woman who wishes to try out for the BSU
women’s track and cross-country teams, and Jane Doe
(“Jane”), a cisgender woman who plays on high school
varsity teams and feared that her sex would be “disputed”
                       HECOX V. LITTLE                     21


under the Act due to her masculine presentation, filed this
lawsuit against Governor Little, Idaho Superintendent of
Public Instruction Sherri Ybarra, and various school officials
at both the high school and collegiate level (collectively,
“Idaho”). They sought a declaratory judgment that the Act
violates Title IX and the United States Constitution,
including the Equal Protection Clause, and preliminary and
permanent injunctions against the Act’s enforcement, as well
as an award of costs, expenses, and reasonable attorneys’
fees.
    On May 26, 2020, Madison (“Madi”) Kenyon and Mary
(“MK”) Marshall (collectively, “the Intervenors”) were
permitted to intervene in this case. Intervenors are cisgender
women residing in Idaho and collegiate athletes who run
track and cross-country on scholarship at Idaho State
University. In 2019, both athletes competed against and lost
to June Eastwood, a transgender woman athlete at the
University of Montana, and found it a “discouraging” and
“deflating” experience.
    On April 30, 2020, Plaintiffs moved for preliminary
injunctive relief based solely on their equal protection
claims. The district court issued preliminary injunctive
relief in August 2020, ruling that both Plaintiffs were likely
to succeed on the merits of their equal protection claims and
would suffer irreparable harm if the injunction was not
granted, and that the balance of equities weighed in favor of
an injunction. Idaho and the Intervenors (collectively, the
“Appellants”) timely appealed.
    We first held oral argument in this appeal on May 3,
2021. At that time, Lindsay informed the court that she had
tried out for and failed to make the women’s track team and
that she subsequently withdrew from BSU classes in late
22                        HECOX V. LITTLE


October 2020. Because the parties’ arguments raised several
unanswered factual questions as to whether Lindsay’s claim
was moot, we remanded the case to the district court for
further factual development and findings on justiciability
questions on June 24, 2021.
    On July 18, 2022, the district court issued factual
findings and concluded that Lindsay’s claim was not moot.
We affirmed the district court’s determination that Lindsay’s
claim was not moot in a separate unanimous order issued on
January 30, 2023. See Hecox v. Little (Hecox II), No. 20-
35813, 

, at *1 (9th Cir. Jan. 30, 2023). 7
We then asked the parties to brief us on which claims
remained for decision in this appeal and any intervening
authority. The parties agree that the only issue that we must
decide is whether the district court abused its discretion in
issuing the preliminary injunction.
                II. STANDARD OF REVIEW
    We review a district court’s grant of a preliminary
injunction for an abuse of discretion. Olson v. California, 

 (9th Cir. 2023). That said, “legal issues
underlying the injunction are reviewed de novo because a
district court would necessarily abuse its discretion if it

7
  In our January order, we determined that Lindsay’s claim was not moot
when she withdrew from BSU in October 2020, because when she left
she expressed a concrete plan to re-enroll and try out for BSU sports
teams. Hecox II, 

 at *1. Lindsay followed through on
those plans by re-enrolling at BSU after she established Idaho state
residency and training to participate in women’s sports teams. 

Indeed, Lindsay plans to try out again for the BSU women’s cross-
country and track teams in Fall 2023, and has been playing for the BSU
women’s club soccer team since Fall 2022. 

. Absent the
preliminary injunction against the Act’s enforcement, Lindsay would be
banned from participating on the BSU women’s club soccer team. 

                        HECOX V. LITTLE                      23


based its ruling on an erroneous view of law.” adidas Am.,
Inc. v. Skechers USA, Inc., 

 (9th Cir. 2018)
(quoting GoTo.com, Inc. v. Walt Disney Co., 

 (9th Cir. 2000)); see also Sw. Voter Registration Educ.
Project v. Shelley, 

, 918 (9th Cir. 2003). We do
“not ‘determine the ultimate merits’” of the case, “but rather
‘determine only whether the district court correctly distilled
the applicable rules of law and exercised permissible
discretion in applying those rules to the facts at hand.’”
Saravia for A.H. v. Sessions, 

, 1141–42 (9th
Cir. 2018) (quoting Fyock v. Sunnyvale, 

(9th Cir. 2015)). However, we will reverse a grant of the
preliminary injunction if the district court “based its decision
. . . on clearly erroneous findings of fact.” Does 1-5 v.
Chandler, 

 (9th Cir. 1996).
    We review the scope of a preliminary injunction for an
abuse of discretion. California v. Azar, 

(9th Cir. 2018).
           III. PRELIMINARY INJUNCTION
    “A preliminary injunction is ‘an extraordinary and
drastic remedy, one that should not be granted unless the
movant, by a clear showing, carries the burden of
persuasion.’” Lopez v. Brewer, 

 (9th Cir.
2012) (quoting Mazurek v. Armstrong, 

(1997) (per curiam) (emphasis in original)). “A plaintiff
seeking a preliminary injunction must establish that he is
likely to succeed on the merits, that he is likely to suffer
irreparable harm in the absence of preliminary relief, that the
balance of equities tips in his favor, and that an injunction is
in the public interest.” Winter v. Nat. Res. Def. Council, Inc.,

 (2008). “When the government is a party,
24                      HECOX V. LITTLE


these last two factors merge.” Drakes Bay Oyster Co. v.
Jewell, 

 (9th Cir. 2014).
        A.      Likelihood of Success on the Merits
    The primary issue presented by this appeal is whether the
district court abused its discretion in concluding that Lindsay
was likely to succeed on the merits of her equal protection
challenge. The Fourteenth Amendment provides that “[n]o
State shall . . . deny to any person within its jurisdiction the
equal protection of the laws.” U.S. Const. amend. XIV, § 1.
In other words, “all persons similarly situated should be
treated alike.” City of Cleburne, Tex. v. Cleburne Living Ctr.,

 (1985). The state may not discriminate
against classes of people in an “arbitrary or irrational” way
or with the “bare . . . desire to harm a politically unpopular
group.” 

 at 446–47.
    When considering an equal protection claim, we
determine what level of scrutiny applies to a classification
under a law or policy, and then decide whether the policy at
issue survives that level of scrutiny. Our “general rule is that
legislation is presumed to be valid and will be sustained if
the classification drawn by the statute is rationally related to
a legitimate state interest,” 

, otherwise known as
rational basis review. However, as gender classifications
“generally provide[] no sensible ground for differential
treatment,” 

 “‘all gender-based classifications today’
warrant ‘heightened scrutiny.’” VMI, 

(quoting J.E.B. v. Alabama ex rel. T.B., 

(1994)). Under heightened scrutiny, “a party seeking to
uphold government action based on sex must establish an
‘exceedingly persuasive justification’ for the classification.”

 at 524 (quoting Mississippi Univ. for Women v. Hogan,

 (1982)).
                        HECOX V. LITTLE                      25


            1.      Heightened scrutiny applies.
    The district court did not err in concluding that
heightened scrutiny applies because the Act discriminates
against transgender women by categorically excluding them
from female sports, as well as on the basis of sex by
subjecting all female athletes, but no male athletes, to
invasive sex verification procedures to implement that
policy. Appellants contend that the Act classifies based only
on sex, not “transgender status,” and permissibly excludes
“biological males” from female sports under our precedent.
See, e.g., Clark, ex rel. Clark v. Arizona Interscholastic Ass’n
(“Clark I”), 

, 1131–32 (9th Cir. 1982) (holding
that excluding boys from a girls’ high school volleyball team
was permissible to redress past discrimination against
women athletes and to promote equal opportunity for
women). We conclude that while the Act certainly classifies
on the basis of sex, it also classifies based on transgender
status, triggering heightened scrutiny on both grounds.
  a. The Act discriminates based on transgender status.
    Appellants argue that the Act does not discriminate based
on transgender status because “[t]he distinction and statutory
classification is based entirely on [biological] sex, not
gender identity.” They assert that the Act’s definition of
“biological sex” describes only the “physiological
differences between the sexes relevant to athletics.” But the
Act explicitly references transgender women, as did its
legislative proponents, and its text, structure, purpose, and
effect all demonstrate that the Act categorically bans
transgender women and girls from public school sports
teams that correspond with their gender identity.
    Section 33-6202 straightforwardly sets forth the
“legislative findings and purpose” of the Act, and makes
26                     HECOX V. LITTLE


clear that its animating purpose was to ban transgender
women from “biologically female” teams. These findings
explicitly discuss transgender women athletes by stating that
“a man [sic] who identifies as a woman and is taking cross-
sex hormones ‘had an absolute advantage’ over female
athletes,” and noting that “[t]he benefits that natural
testosterone provides to male athletes is [sic] not diminished
through the use of puberty blockers and cross-sex
hormones.” 

(11).
    During the legislative debate on H.B. 500, the Act’s
supporters stated repeatedly that the Act’s purpose was to
ban transgender women athletes from participating on
female athletic teams in Idaho. Representative Ehardt, who
introduced the bill, characterized the law as a “preemptive”
strike that would allow Idaho to “remove [transgender
women] and replace them with the young gal that should
have been on the team.” Representative Ehardt reiterated
that the Act would require transgender women to “compete
on the side of those biological boys and men with whom they
look or, about whom they look alike.” Much of the
legislative debate centered around two transgender women
athletes running track in Connecticut high schools, as well
as one running college track in Montana, and the potential
“threat” those athletes presented to female athletes in Idaho.
When the then-Idaho Attorney General Wasden expressed
concerns about the Act’s constitutionality, he expressly
described it as “targeted toward transgender and intersex
athletes.”
    The plain language of section 33-6203 bans transgender
women from “biologically female” teams. The Act divides
sports teams into three categories based on biological sex:
“(a) Males, men, or boys; (b) Females, women, or girls; or
(c) Coed or mixed.” 

 § 33-6203(1). Sports designated for
                       HECOX V. LITTLE                     27


“females, women, or girls” are not open to students of the
male sex. Id. § 33-6203(2). And the methods for
“verify[ing] the student’s biological sex” are restricted to
“reproductive anatomy, genetic makeup, or normal
endogenously produced testosterone levels.” Id. § 33-
6203(3). However, most gender-affirming medical care for
transgender females, especially minors, will not or cannot
alter the characteristics described in the only three
verification methods prescribed by the Act, thus effectively
banning transgender females from female sports. As the
district court determined, “the overwhelming majority of
women who are transgender have XY chromosomes,” which
indicate the male sex, and transgender women cannot change
that genetic makeup when they transition. Hecox, 479 F.
Supp. 3d at 984. Similarly, as medical expert Dr. Deanna
Adkins opined, many transgender women and girls do not
undergo gender-affirming genital surgery to alter their
external “reproductive anatomy,” often because they cannot
afford it or it is inappropriate for their individual needs.
    Further, because surgery cannot change transgender
women’s internal reproductive anatomy by creating ovaries,
Dr. Adkins testified that transgender women “typically
continue to need estrogen therapy” even after surgery and
can never alter their “endogenously produced”—or naturally
produced—testosterone levels. By contrast, the Act does not
allow sex to be verified by a transgender woman’s levels of
circulating testosterone, which can be altered through
medical treatment. A transgender woman like Lindsay, for
example, can lower her circulating testosterone levels
through hormone therapy to conform to elite athletic
regulatory guidelines, but cannot currently alter the
endogenous testosterone that her body naturally produces.
Yet the district court found and the record before it supports
28                          HECOX V. LITTLE


that circulating testosterone is the “one [sex-related] factor
that a consensus of the medical community appears to agree”
actually affects athletic performance. Id.
    Appellants suggest that “biological sex” is a neutral and
well-established medical and legal concept, rather than one
designed precisely by the Idaho legislature to exclude
transgender and intersex people. 8 But the Act’s definition of

8
  In supplemental briefing, Appellants also argue that the Supreme
Court’s recent decisions in Dobbs v. Jackson Women’s Health Org., 

 (2022) and N.Y. State Rifle & Pistol Ass’n, Inc. v. Bruen, 

 (2022) “are fatal to Hecox’s claim” because the ratifiers of
the Fourteenth Amendment would have understood “male” to
correspond to the definition of “biological male” written into the Act.
We fail to see how Dobbs, a substantive due process decision about
whether the federal Constitution protects a woman’s right to obtain an
abortion, and Bruen, a Second Amendment decision about gun rights, are
relevant to an equal protection claim based on sex discrimination, unless
Appellants are suggesting that the Framers would have understood the
term “biological sex” by reference to reproductive anatomy, genetic
make-up, or normal endogenously produced testosterone levels. Indeed,
the ratifiers of the Fourteenth Amendment would certainly not have
understood the Act’s definition of “biological sex.” For example, the
drafters of the Fourteenth Amendment would have had no concept of
what “endogenously produced testosterone levels” meant in 1868,
because testosterone was not named and isolated as a hormone until
1935. See John M. Tomlinson, The Testosterone Story, Trends in
Urology & Men’s Health 34, 35 (2012). Similarly, the ratifiers would
not have understood how “genetic makeup” influences sex, as
chromosomes were first discovered by Walther Flemming in 1882. D.W.
Rudge, The Man Who Invented the Chromosome, 97 Heredity 136, 136
(2006) (reviewing Oren Harman, The Man Who Invented the
Chromosome: A Life of Cyril Darlington (2004)).
  Moreover, there is evidence that transgender people have existed since
ancient times. See generally Lauren Talalay, The Gendered Sea:
Iconography, Gender, and Mediterranean Prehistory, in THE
ARCHEOLOGY OF MEDITERRANEAN PREHISTORY 130–33 (Emma Blake
                             HECOX V. LITTLE                               29


“biological sex” is likely an oversimplification of the
complicated biological reality of sex and gender. As Dr.
Joshua Safer, Executive Director of the Center for
Transgender Medicine and Surgery at Mount Sinai,
explained in his declaration, citing the Endocrine Society
Guidelines:

         The phrase “biological sex” is an imprecise
         term that can cause confusion. A person’s sex
         encompasses the sum of several biological
         attributes, including sex chromosomes,
         certain genes, gonads, sex hormone levels,
         internal and external genitalia, other
         secondary sex characteristics, and gender
         identity. These attributes are not always
         aligned in the same direction.

Indeed, two percent of all babies are born “intersex,” or with
“a wide range of natural variations in physical traits—
including external genitals, internal sex organs,

& A. Bernard Knapp eds., 2005). Appellants appear to argue that
because transgender people were marginalized in 1868, they should be
afforded no constitutional protections on the basis of their transgender
status. But this argument would undermine decades of Supreme Court
precedent striking down laws that discriminate on the basis of sex. See
Reed v. Reed, 

 (1971) (holding that an Idaho statute that
preferenced men as administrators of estates “ma[d]e the very kind of
arbitrary legislative choice forbidden by the Equal Protection Clause of
the Fourteenth Amendment”); Frontiero v. Richardson, 

 (1973) (“[S]tatutory distinctions between the sexes often have the
effect of invidiously relegating the entire class of females to inferior legal
status without regard to the actual capabilities of its individual
members.”); see also Weinberger v. Weisenfeld, 

(1975); Craig v. Boren, 

 (1976); Duren v. Missouri,

 (1979); VMI, 

.
30                     HECOX V. LITTLE


chromosomes, and hormones—that do not fit typical binary
notions of male and female bodies.” Br. of Amici Curiae
InterACT at 3–4. Intersex people who identify as women
are equally banned under the Act from playing on Idaho
women’s teams. And while scientists are not fully certain
why some people identify as transgender, it appears likely
that there is some biological explanation—such as
gestational exposure to elevated levels of testosterone—that
causes certain individuals to identify as a different gender
than the one assigned to them at birth. See AAP Br. at 14.
    We have previously rejected an argument like Appellants
raise here—that because section 33-6203 uses “biological
sex” in place of the word “transgender,” it is not targeted at
excluding transgender girls and women. In Latta v. Otter,

 (9th Cir. 2014), we held that Idaho and Nevada
laws that banned same-sex marriage discriminated on the
basis of sexual orientation, even though the laws did so by
classifying couples based on “procreative capacity” instead
of sexual orientation. 

 at 467–68. We explained:

       Effectively if not explicitly, [defendants]
       assert that while these laws may disadvantage
       same-sex couples and their children,
       heightened scrutiny is not appropriate
       because differential treatment by sexual
       orientation is an incidental effect of, but not
       the reason for, those laws. However, the laws
       at issue distinguish on their face between
       opposite-sex couples, who are permitted to
       marry and whose out-of-state marriages are
       recognized, and same-sex couples, who are
       not permitted to marry and whose marriages
       are not recognized.           Whether facial
                       HECOX V. LITTLE                      31


       discrimination exists “does not depend on
       why” a policy discriminates, “but rather on
       the explicit terms of the discrimination.”
       Hence, while the procreative capacity
       distinction that defendants seek to draw could
       represent a justification for the discrimination
       worked by the laws, it cannot overcome the
       inescapable conclusion that Idaho and
       Nevada do discriminate on the basis of sexual
       orientation.

 at 467–68 (quoting Int’l Union, United Auto., Aerospace
& Agr. Implement Workers of Am., UAW v. Johnson
Controls, Inc., 

 (1991)). Here, the Act’s
use of “biological sex” functions as a form of “[p]roxy
discrimination.” Pac. Shores Props., LLC v. City of Newport
Beach, 

, 1160 n.23 (9th Cir. 2013). The
definition of “biological sex” in the Act is written with
“seemingly neutral criteria that are so closely associated with
the disfavored group that discrimination on the basis of such
criteria is, constructively, facial discrimination against the
disfavored group.” Id.; see also Bray v. Alexandria Women’s
Health Clinic, 

 (1993) (“A tax on wearing
yarmulkes is a tax on Jews.”); Lawrence v. Texas, 

 (2003) (“When homosexual conduct is made
criminal by the law of the State, that declaration in and of
itself is an invitation to subject homosexual persons to
discrimination . . . .”). The Act’s specific classification of
“biological sex” has similarly been carefully drawn to target
transgender women and girls, even if it does not use the word
“transgender” in the definition.
   Adams ex rel. Kasper v. School Bd. of St. Johns Cnty.
(“Adams”), 

 (11th Cir. 2022) (en banc), upon
32                        HECOX V. LITTLE


which Appellants rely to support their argument that the Act
does not discriminate against transgender girls or women, is
inapposite. There, the Eleventh Circuit upheld a lower court
order rejecting an equal protection challenge to a K-12
school policy that provided female, male, and sex-neutral
bathrooms and required male students to use the male-
designated bathrooms, female students to use the female
bathrooms, and accommodated transgender students with
the sex-neutral bathrooms. See 

. The policy
defined “male” and “female” as the gender identified on a
student’s birth certificate. See 

 The Eleventh Circuit
rejected the argument that the policy unconstitutionally
discriminated on the basis of transgender status because it
was “substantially related” to the school district’s important
interest in securing its pupils’ privacy and welfare and was
not targeted at transgender students—at most, it had a
disparate impact upon them which did not rise to the level of
a constitutional violation because no animus was shown. See

. Importantly, in Adams—as opposed to here—
there was “no [record] evidence suggesting that the School
Board enacted the [] policy because of . . . its adverse effects
upon transgender students.” 

 (second alteration in
original) (internal quotation marks omitted). To the contrary,
the school district in Adams had studied the issues raised by
the LGBTQ community and had also enacted policies that
affirmatively accommodated transgender students. 9
Moreover, bathrooms by their very nature implicate




9
 Although Adams is plainly distinguishable, we express no view on the
merits of the decision.
                         HECOX V. LITTLE                         33


important privacy interests and are not the equivalent of
athletic teams. 10
    Appellants likewise misrely on a footnote in Geduldig v.
Aiello, 

 (1974), for the proposition that a
legislative classification based on biological sex is not a
classification based on transgender status. See 

 at 496
n.20. In Geduldig, the Supreme Court stated that a
classification based on pregnancy is not per se a
classification based on sex, even though “it is true that only
women can become pregnant.” 

 However, the Court held
that “distinctions involving pregnancy” that are “mere
pretexts designed to effect an invidious discrimination” are
subject to heightened scrutiny. 

 Here, it appears that the
definition of “biological sex” was designed precisely as a
pretext to exclude transgender women from women’s
athletics—a classification that Geduldig prohibits.
    Finally, Appellants contend that the Act does not
discriminate based on transgender status because the “Act
does not prohibit biologically female athletes who identify
as male from competing on male sports teams consistent
with their gender identity.” But a law is not immune to an
equal protection challenge if it discriminates only against
some members of a protected class but not others. See, e.g.,
Rice v. Cayetano, 

, 516–17 (2000) (“Simply
because a class . . . does not include all members of [a] race
does not suffice to make the classification race neutral.”);
Nyquist v. Mauclet, 

, 7–9 (1977) (holding that
singling out some but not all undocumented immigrants for
discrimination constituted a “classification based on
alienage”); Mathews v. Lucas, 

, 504 n.11 (1976)

10
  For one, the functions of the bathroom are intended to be private,
unlike sporting events.
34                       HECOX V. LITTLE


(“That the statutory classifications challenged here
discriminate among illegitimate children does not mean, of
course, that they are not also properly described as
discriminating between legitimate and illegitimate
children.”).
b. Heightened scrutiny applies because the                   Act
   discriminates on the basis of transgender status.
    We have previously held that heightened scrutiny applies
to laws that discriminate on the basis of transgender status,
reasoning that gender identity is at least a “quasi-suspect
class.” Karnoski v. Trump, 

, 1200–01 (9th Cir.
2019).
    In Karnoski, we reviewed an injunction against the
implementation of a 2017 Presidential Memorandum and
Departments of Defense and Homeland Security policies
that effectively precluded transgender individuals from
serving in the U.S. military. 

. The district court
had applied strict scrutiny in enjoining the policy, while the
government argued that the policy should be reviewed under
a rational basis standard. 

. We held that because
the implementing policy “on its face treats transgender
persons differently than other persons . . . something more
than rational basis but less than strict scrutiny applies.” 

. We therefore adopted the heightened scrutiny
approach of VMI and Witt v. Dep't of Air Force, 

 (9th Cir. 2008), to review the military’s ban on
transgender persons who experienced gender dysphoria or
who have undergone gender transition. 11 

 We are thus

11
   The Supreme Court determined in VMI that for “cases of official
classification based on gender” a reviewing court must apply a
“heightened review standard” and determine whether the state has
demonstrated an “exceedingly persuasive justification” for the
                            HECOX V. LITTLE                              35


compelled to review the constitutionality of the Act under
heightened scrutiny as it classifies based on transgender
status.
    Moreover, discrimination on the basis of transgender
status is a form of sex-based discrimination. It is well-
established that sex-based classifications are subject to
heightened scrutiny. See VMI, 518 U.S. at 533–34. The
Supreme Court recently held in the Title VII context that “it
is impossible to discriminate against a person for being . . .
transgender without discriminating against that individual
based on sex.” Bostock v. Clayton Cnty., Ga., 

 (2020). 12 Indeed, “[m]any courts . . . have held
that various forms of discrimination against transgender
individuals constitute sex-based discrimination for purposes
of the Equal Protection Clause because such policies punish
transgender persons for gender non-conformity, thereby
relying on sex stereotypes.” Grimm v. Gloucester Cnty. Sch.
Bd., 

, 608 (4th Cir. 2020) (applying heightened
scrutiny to a bathroom policy); see also Whitaker By
Whitaker v. Kenosha Unified Sch. Dist. No. 1 Bd. of Educ.,

classification. 518 U.S. at 533–34. In Witt, we applied a “heightened
scrutiny” approach to the military’s “Don’t Ask, Don’t Tell” policy for
gay and lesbian servicemembers, determining that “when the
government attempts to intrude upon the personal and private lives of
homosexuals . . . the government must advance an important
governmental interest, the intrusion must significantly further that
interest, and the intrusion must be necessary to further that interest.” 

.
12
  See also Nondiscrimination on the Basis of Sex in Education Programs
or Activities Receiving Federal Financial Assistance, 

, 41571 (proposed July 12, 2022) (to be codified at 34 C.F.R. pt.
106) (clarifying that “discrimination on the basis of sex” under Title IX
includes discrimination based on “sex stereotypes, sex characteristics . . .
and gender identity”).
36                         HECOX V. LITTLE

 (7th Cir. 2017), abrogated on other
grounds, Illinois Republican Party v. Pritzker, 

(7th Cir. 2020) (same); Brandt ex rel. Brandt v. Rutledge, 

, 670–71 & n.4 (8th Cir. 2022) (applying
heightened scrutiny to affirm a preliminary injunction
against a law that prohibited “gender transition procedures”
because the law discriminated on the basis of sex); Eknes-
Tucker v. Marshall, 

, 1147 (M.D. Ala.
2022) (applying heightened scrutiny to a law that prohibited
various medical treatments for gender dysphoria in
minors). 13
      c. Heightened scrutiny applies because the Act
      discriminates against all Idaho female student athletes.
    In addition to discriminating on the basis of transgender
status, the Act discriminates on the basis of sex, because only
women and girls who want to compete on Idaho school
athletic teams, and not male athletes, are subject to the sex
dispute verification process. The Act expressly states that
only “[a]thletic teams or sports designated for females,
women, or girls shall not be open to students of the male
sex.” 

(2). The Act does not ban
“biological females” from “teams or sports designated for
males.” Therefore, transgender and cisgender men who
compete on male-designated teams are not subject to the sex


13
   Both Idaho and the Intervenors note that the Eleventh Circuit
expressed “grave doubt” in a footnote in Adams that transgender people
constitute a “quasi-suspect class.” Adams, 

 n.5 (internal
quotation marks omitted). This dicta is unpersuasive, as the Eleventh
Circuit declined to decide the issue or further opine on its “doubts.” In
any event, as a three-judge panel we cannot overrule the binding
precedent of our circuit. See Miller v. Gammie, 

 (9th
Cir. 2003).
                            HECOX V. LITTLE                             37


dispute verification process. The sex dispute verification
process simply does not apply to male athletes. 14
    The Act thus classifies on the basis of sex by subjecting
only women and girls, whether cisgender or transgender, to
the risk and humiliation of having their sex “disputed” and
then suffering intrusive medical testing as a prerequisite for
participation on school sports teams. And where women and
girls are subject to separate requirements for educational
opportunities that are “unequal in tangible and intangible”
ways from those for men, those requirements are tested
under heightened scrutiny. VMI, 

.
2.        The Act likely does not survive heightened scrutiny.
    The district court correctly concluded that neither the
categorical ban nor sex dispute verification provisions likely
survive heightened scrutiny. Heightened scrutiny is a
“demanding” standard, with the burden “rest[ing] entirely on
the State” to demonstrate an “exceedingly persuasive”
justification for its differential treatment. VMI, 

   While the ban discriminates on the basis of transgender status, it is
important to discuss how it discriminates against all young women and
girls. The partial concurrence reads the sex dispute verification
provision as applicable to men and boys who wish to participate on
women and girls’ teams. But this contention disregards that, as the
concurrence itself elsewhere acknowledges, “[e]xisting rules already
prevented boys from playing on girls’ teams before the Act.” Partial
Concurrence at 66 (quoting Hecox, 479 F. Supp. 3d at 982). The record
is devoid of any evidence of “men and boys who wish to participate on
teams designated for women or girls,” id. at 72, in Idaho. However, if
they exist, male-identifying students who wish to play on girls’ teams
will never be subject to the sex dispute verification process, because they
are already banned from participation in women’s teams by virtue of
their identity under existing IHSSA policies. Only women and girls will
be subject to the degrading specter of having their sex disputed and
undergoing invasive and unnecessary medical testing.
38                     HECOX V. 

. To survive heightened scrutiny, the government must
demonstrate “that the [challenged] classification serves
important governmental objectives and that the
discriminatory means employed are substantially related to
the achievement of those objectives.” Id. at 516 (alteration
in original) (internal quotation marks and citations omitted).
Our review under heightened scrutiny is an extremely fact-
bound test, requiring us to “examine [a policy’s] actual
purposes and carefully consider the resulting inequality to
ensure our most fundamental institutions neither send nor
reinforce messages of stigma or second-class status.”
SmithKline Beecham Corp. v. Abbott Labs., 

 (9th Cir. 2014).
    Appellants contend that, “[d]ue to the average
physiological differences” between men and women, the Act
substantially advances the important state interest of
“promot[ing] sex equality . . . by providing opportunities for
female athletes to demonstrate their skill, strength, and
athletic abilities [and] opportunities to obtain recognition
and accolades, college scholarships, and the numerous other
long-term benefits that flow from success in athletic
endeavors.”      

(12).          We have
previously held that furthering women’s equality and
promoting fairness in female athletic teams is an important
state interest. Clark I, 695 F.2d at 1131. However, on the
record before us, the district court correctly determined that
the Act’s means—categorically banning transgender women
and girls from all female athletic teams and subjecting all
female athletes to intrusive sex verification procedures—are
not substantially related to, and in fact undermine, those
asserted objectives.
                       HECOX V. LITTLE                     39


   a. Clark I and Clark II do not control the outcome of
                      Lindsay’s claim.
    Our decisions in Clark I and Clark ex rel. Clark v.
Arizona Interscholastic Ass'n, 

 (9th Cir. 1989)
(“Clark II”) are inapposite. In Clark I and Clark II, we held
that public high schools could constitutionally prohibit male
student athletes from participation on women’s teams in
order to further the important government interest of
“redressing past discrimination against women in athletics
and promoting equality of opportunity between the sexes.”
Clark I, 695 F.2d at 1131.
    Specifically in Clark I, we held that an Arizona
Interscholastic Association policy that separated high school
volleyball teams by gender and prohibited boys from playing
on girls’ teams did not violate the Equal Protection Clause.
Clark I, 695 F.2d at 1127. There, Clark wished to play on
the girls’ volleyball team because his particular high school
did not offer boys’ volleyball teams. Id. We first recognized
that, in applying heightened scrutiny, “the Supreme Court is
willing to take into account actual differences between the
sexes, including physical ones.” Id. at 1229 (citing Michael
M. v. Sonoma Cnty. Superior Ct., 

, 468–69
(1981) (upholding a statutory rape statute that held only
males culpable because only women can become pregnant,
thus furthering the government’s interest in preventing teen
pregnancy)). We concluded that general gender separation
in school sports was substantially related to the
government’s interest in women’s equality in athletics. Id.
at 1131. We reasoned that “due to average physiological
differences, males would displace females to a substantial
extent if they were allowed to compete for positions on the
volleyball team.” Id. Thus, if men were allowed to compete
on the women’s teams, women’s overall athletic
40                       HECOX V. LITTLE


opportunities would decrease, while men’s overall athletic
opportunities would remain greater than women’s.
    Eight years later, in Clark II, the original Clark I
plaintiff’s brother brought a second “mystifying” action
challenging the same policy, arguing that the state “ha[d]
been wholly deficient in its efforts to overcome the effects
of past discrimination against women in interscholastic
athletics, and that this failure vitiate[d] its justification for a
girls-only volleyball team.” Clark II, 886 F.2d at 1193.
Applying Clark I, we affirmed that the gender classification
for Arizona school sports was constitutional. Id. at 1194.
    Appellants argue that “[t]he only difference between
Hecox and the Clark brothers is gender identity,” which does
not change the physiological advantages that “biological
males” have over cisgender women. But this is a false
assumption. First, Lindsay takes medically prescribed
hormone therapy to suppress her testosterone and raise her
estrogen levels. This treatment has lowered her circulating
testosterone levels—which impact athletic prowess and have
slowed her racing times by at least “five to ten percent”—
and her testosterone levels were “well below the levels
required to meet NCAA eligibility for cross country and
track” in Fall 2022, as the district court found. See Hecox,
479 F. Supp. 3d at 946. Lindsay’s treatment has dramatically
altered her bodily systems and secondary sex characteristics.
As the district court found, “it is not clear that transgender
women who suppress their testosterone have significant
physiological advantages over cisgender women,” unlike the
cisgender boys at issue in Clark I and Clark II. Id. at 978.
    Second, as the district court noted, transgender women,
“like women generally . . . have historically been
discriminated against, not favored.” Id. at 977. A recent
                       HECOX V. LITTLE                      41


study by the CDC concluded that “transgender students
reported significantly higher incidents of being bullied,
feeling unsafe traveling to or from school, being threatened
with a weapon at school, and being made to engage in
unwanted sexual relations.” Br. of Amici Curiae GLBTQ
Legal Advocates & Defenders and the National Center for
Lesbian Rights, at 9; see also Whitaker, 

(“There is no denying that transgender individuals face
discrimination, harassment, and violence because of their
gender identity.”). Unlike the policy in Clark I, the Act
perpetuates historic discrimination against both cisgender
and transgender women by categorically excluding
transgender women from athletic competition and subjecting
all women to an invasive sex dispute verification process.
    Moreover, the district court correctly found that “under
the Act, women and girls who are transgender will not be
able to participate in any school sports, unlike the boys in
Clark I, who generally had equal [or greater] athletic
opportunities.” Hecox, 479 F. Supp. 3d at 977. Here, unlike
in Clark I, transgender women are not being denied one
“particular opportunity” to participate on women’s teams
even though their “overall opportunity is not inferior” to that
of women. Clark I, 695 F.2d at 1126. As a practical matter,
the Act bars transgender women and girls in Idaho from all
participation in student athletics—under its explicit terms,
they cannot play on teams that conform to their transgender
status. The argument advanced by Representative Ehardt
that the Act does not discriminate against transgender
women because they can still play on men’s teams is akin to
the argument we rejected in Latta, that same-sex marriage
bans do not discriminate against gay men because they are
free to marry someone of the opposite sex. See Latta, 

 (holding unconstitutional two marriage bans that
42                      HECOX V. LITTLE


“distinguish on their face between opposite-sex couples who
are permitted to marry and whose out-of-state marriages are
recognized, and same-sex couples, who are not permitted to
marry and whose marriages are not recognized”). As
medical expert Dr. Jack Turban stated, “forcing [transgender
students] to play on a sports team that does not match their
gender identity would damage their mental health” by
“forcing them to express themselves as cisgender.” Lindsay
declared that she would never compete on a men’s team, as
it would be “embarrassing and painful to be forced onto a
team for men—like constantly wearing a big sign that says
‘this person is not a “real” woman.’”
    The district court also found that, on the record before it,
“transgender women have not and could not ‘displace’
cisgender women in athletics ‘to a substantial extent.’”
Hecox, 479 F. Supp. 3d at 977 (quoting Clark I, 695 F.2d at
1131). Appellants misrely on a single line from Clark II to
argue that the participation of just one transgender woman
on a team risks displacing any individual cisgender woman:
“If males are permitted to displace females on the school
volleyball team even to the extent of one player like Clark,
the goal of equal participation by females in interscholastic
athletics is set back, not advanced.” Clark II, 886 F.2d at
1193. This statement, however, was made in response to the
argument in Clark II that because sex separation had not
fully met Arizona’s goal of equality of participation in
sports, Arizona no longer had an important interest in the
policy. We did not think Clark’s proposed remedy for the
inequality of opportunities for female athletes—allowing
him to play on the girls’ teams—would advance the “goal of
equal participation by females in interscholastic sports.” Id.
Because transgender women represent about 0.6 percent of
the general population, the district court did not err in finding
                        HECOX V. LITTLE                       43


it unlikely that they would displace cisgender women from
women’s sports.
 b. The categorical ban provision likely fails heightened
                          scrutiny.
    Nor did the district court clearly err, see Doe v. Snyder,

 (9th Cir. 2022), in finding that the Act’s
categorical ban provision failed heightened scrutiny because
it was not substantially related to its stated goals of equal
participation and opportunities for women athletes. The
district court found that the categorical ban provision did not
advance its asserted objectives for three reasons, none of
which were “illogical, implausible, or without support in
inferences that may be drawn from the facts in the record.”
Pom Wonderful LLC v. Hubbard, 

 (9th
Cir. 2014) (citation omitted). Moreover, the Act’s sweeping
prohibition on transgender female athletes in Idaho—
encompassing all students, regardless of whether they have
gone through puberty or hormone therapy, and without any
evidence of transgender athletes displacing female athletes
in Idaho—is too overbroad to satisfy heightened scrutiny.
    First, the district court found that there was scientifically
“no evidence to suggest a categorical bar against a
transgender female athlete’s participation in sports is
required in order to promote ‘sex equality’ or to ‘protect
athletic opportunities for females’ in Idaho.” Hecox, 479 F.
Supp. 3d at 978–79. Appellants argue that the district court
misread the available medical evidence, which they contend
demonstrates that endogenous testosterone levels give
“biological males” a permanent athletic advantage over
cisgender women. However, the district court did not err by
relying upon the testimony of a medical expert, Dr. Safer,
who testified that there was a medical consensus that the
44                      HECOX V. LITTLE


“primary known driver of differences in athletic
performance between elite male athletes and elite female
athletes” is “the difference in [circulating] testosterone”
levels, as opposed to “endogenously produced” testosterone
levels, and “[a] person’s genetic make-up and internal and
external reproductive anatomy are not useful indicators of
athletic performance and have not been used in elite
competition for decades.” The district court credited Dr.
Safer’s opinion that a transgender woman who endured
hormone therapy to lower her circulating levels of
testosterone would likely not have different “physiological
characteristics” than a cisgender woman that would lead to
enhanced athletic prowess.
    Appellants presented contrary medical testimony by Dr.
Gregory Brown that hormone therapy suppression did not
eliminate all of the physiological advantages that an
individual experiences through male puberty. However, as
the district court found, Dr. Brown’s opinion was not
supported by the studies he relied upon, because the majority
of the studies he cited discussed the average differences
between male and female athletes in general, not the
difference between transgender and cisgender women
athletes. And one study that he cited—the Handelsman
study—actually came to the opposite conclusion, concluding
that “evidence makes it highly likely that the sex difference
in circulating testosterone of adults explains most, if not all,
of the sex differences in sporting performance.”
    The studies that the Idaho legislature relied upon to
conclude that the benefits of “natural testosterone” could not
be diminished through hormone therapy were likewise
flawed. For example, one of the studies was altered after
peer review to remove its conclusions regarding transgender
athletes, and, as Idaho admits, that “study and its findings
                           HECOX V. LITTLE                            45


were not based specifically on transgender athletes.” The
legislature also relied on a study by Professor Coleman, who
personally urged Governor Little to veto the bill because the
legislature misinterpreted her work.
    Moreover, as the district court found, the Act sweeps
much more broadly than simply excluding transgender
women who have gone through “endogenous puberty.” The
Act’s categorical ban includes transgender students who are
young girls in elementary school or even kindergarten.
Other transgender women take puberty blockers and never
experience endogenous puberty, yet the Act indiscriminately
bars them from participation in women’s student athletics,
regardless of their testosterone levels. Although the
scientific understanding of transgender women’s potential
physiological advantage is fast-evolving and somewhat
inconclusive, we are limited to reviewing the record before
the district court. And the record in this case does not
ineluctably lead to the conclusion that all transgender
women, including those like Lindsay who have gone through
hormone therapy, have a physiological advantage over
cisgender woman.
    Second, as the district court found, there was very little
anecdotal evidence at the time of the Act’s passage that
transgender women had displaced or were displacing
cisgender women in sports or scholarships or like
opportunities. In 2020, both the IOC and the NCAA required
transgender women to suppress their testosterone for only a
year for eligibility to compete on women’s teams. 15 The

15
   Although today the IOC and NCAA policies evaluate eligibility for
transgender participation in athletics on a sport-by-sport basis, neither
policy endorses the categorical exclusion of transgender women. They
instead favor an “evidence-based approach” with “no presumption of
46                         HECOX V. LITTLE


record before the district court includes anecdotal evidence
of only four transgender athletes who had ever competed in
cisgender women’s sports, including two high school
runners who competed in Connecticut and were
subsequently defeated by cisgender women in competition.
While the Intervenors state they were defeated by a
transgender athlete, June Eastwood, in a running
competition at the University of Montana, Eastwood
eventually lost to a different cisgender athlete in that same
competition. Lindsay’s own athletic career belies the
contention that transgender women who have undergone
male puberty have an absolute advantage over cisgender
women: she has never qualified for BSU’s track team despite
trying out in Fall 2020.
    There is likewise no evidence in the record of a
transgender woman receiving an athletic scholarship over a

advantage.” Int’l Olympics Comm., IOC Framework on Fairness,
Inclusion and Non-Discrimination on the Basis of Gender Identity and
Sex                  Variations               4                  (2021),
https://stillmed.olympics.com/media/Documents/Beyond-the-
Games/Human-Rights/IOC-Framework-Fairness-Inclusion-Non-
discrimination-2021.pdf#page=4 (last visited June 6, 2023); see also
Nat’l Collegiate Athletics Ass’n, Transgender Student-Athlete
Participation           Policy        (April        17,           2023),
https://www.ncaa.org/sports/2022/1/27/transgender-participation-
policy.aspx (last visited May 24, 2023). And while the World Athletics
Council, the international governing body for track and field, recently
adopted a more stringent policy of categorically excluding post-
pubescent transgender women from elite athletic competitions, its policy
does not bar transgender women who have not experienced endogenous
puberty from eligibility. See Press Release, World Athletics Counsel,
World Athletics Council Decides on Russia, Belarus, and Female
Eligibility (Mar. 23, 2023), https://worldathletics.org/news/press-
releases/council-meeting-march-2023-russia-belarus-female-eligibility
(last visited May 24, 2023).
                       HECOX V. LITTLE                     47


cisgender woman in Idaho. Moreover, as the district court
noted, the Act’s broad sweep—banning transgender
women’s participation not just in high school and college
athletics, but elementary school and club sports—“belies any
genuine concern with an impact on athletic scholarships,”
which are relevant to only a small portion of the competitive
teams encompassed by the Act. Hecox, 479 F. Supp. 3d at
983.
    Of course, when applying heightened scrutiny, we “must
accord substantial deference to the predictive judgments” of
legislative bodies. Turner Broad. Sys., Inc. v. FCC, 

 (1994). But this does not “insulate[]” predictive
judgments “from meaningful judicial review altogether.” 

. “[U]nsupported legislative conclusions as to whether
particular policies will have societal effects of the sort at
issue in this case—determinations which often, as here,
implicate constitutional rights—have not been afforded
deference by the [Supreme] Court.” Latta, 

;
see also Lopez-Valenzuela v. Arpaio, 

 (9th
Cir. 2014) (“[T]he absence of any credible showing that the
[challenged law] addressed a particularly acute problem”
was “quite relevant” to a showing that the law did not
survive heightened scrutiny.). A vague, unsubstantiated
concern that transgender women might one day dominate
women’s athletics is insufficient to satisfy heightened
scrutiny.
    Third, the district court questioned the Act’s true
objectives, ruling that Idaho’s interest was not in “promoting
sex equality” but “excluding transgender women and girls
from women’s sports entirely.” Hecox, 469 F. Supp. 3d at
983. Before the Act’s passage, the existing NCAA and Idaho
state rules governed transgender women’s participation as
measured by circulating testosterone levels, and there was
48                           HECOX V. LITTLE


no record evidence that transgender women and girls
threatened to dominate female student athletics. The record
indicates that Idaho may have wished “to convey a message
of disfavor” toward transgender women and girls, who are a
minority in this country. See Latta, 

. And
“[t]his is a message that Idaho . . . simply may not send”
through unjustifiable discrimination. 16 

.


16
   Other federal and state courts have enjoined transgender sports bans,
and no categorical ban has yet been upheld on appeal. See Doe v. Horne,
No. CV-23-00185-TUC-JGZ, 

, at *1 (D. Ariz. July 20,
2023) (granting a preliminary injunction against Arizona’s categorical
ban under the Equal Protection Clause and Title IX); A.M. by E.M. v.
Indianapolis Pub. Sch., 

, 969 (S.D. Ind. July 26,
2022), appeal dismissed, No. 22-2332, 

, at *1 (7th Cir.
Jan. 19, 2023) (granting a preliminary injunction against transgender
participation in athletics under Title IX); Roe v. Utah High School
Activities Ass'n, No. 220903262, 

, at *1 (Utah Dist.
Ct. Aug. 19, 2022) (granting a preliminary injunction against a
categorical ban under the Utah Constitution’s equivalent of an equal
protection clause); see also Barrett v. State of Mont., No. DV-21-581B,
at *5–7 (Mont. Dist. Ct. Sept. 14, 2022) (granting summary judgment
against a categorical ban on the ground that only Montana public
university officials have the authority to regulate athletic competition in
public universities).
   We note that in B. P. J. v. W. Va. State Bd. of Educ., 

 (S.D.W. Va. 2021), a district court enjoined West Virginia’s similar
categorical ban, finding that B.P.J., a twelve-year-old transgender girl
who wished to play middle school athletics, was likely to succeed on the
merits of her equal protection and Title IX claims. See 

 at 353–57. In
January 2023, the district court reversed course and granted summary
judgment to the state, dissolving the injunction and holding that the
state’s definition of “biological sex” was “substantially related to athletic
performance and fairness in sports.” B. P. J. v. W. Va. State Bd. of Educ.,
No. 21-00316, 

, at *8 (S.D.W. Va. Jan. 5, 2023). The
Fourth Circuit stayed the district court’s January order pending appeal,
and the Supreme Court denied the application to vacate that injunction.
                           HECOX V. LITTLE                           49


     We must “reject measures that classify unnecessarily and
overbroadly by gender when more accurate and impartial
lines can be drawn.” Sessions v. Morales-Santana, 137 

, 63 n.13 (2017). While the Act purports to further
athletic opportunities for Idaho’s female students, the district
court correctly concluded that the Act does not further this
goal, and in fact “appears unrelated to the interests the Act
purportedly advances.” Hecox, 470 F. Supp. 3d at 979. And
“[i]ntentional discrimination on the basis of gender by state
action violates the Equal Protection Clause[] where, as here,
the discrimination serves to ratify and perpetuate invidious,
archaic, and overbroad stereotypes.” J.E.B. v. Alabama ex
rel. T.B., 

 (1994). Thus, we need not and
do not decide what policy would justify the exclusion of
transgender women and girls from Idaho athletics under the
Equal Protection Clause, because the total lack of means-end
fit here demonstrates that the Act likely does not survive
heightened scrutiny.
     c. The sex dispute verification provision likely fails
                      heightened scrutiny.
    The district court also correctly concluded that the sex
verification provision likely failed heightened scrutiny
because Idaho failed to demonstrate an “exceedingly
persuasive justification,” VMI, 

, for
subjecting only young women and girls to the humiliating
and intrusive burden of the sex verification process. 17

See W. Va. v. B. P. J., by Jackson, 

 (2023). As of this
writing, transgender girls such as B. P. J. may participate in West
Virginia school athletics.
17
  Idaho contends that we should dismiss the challenge to the sex dispute
verification provision of the Act, because the district court primarily
analyzed the provision’s constitutionality as to Jane’s claim, which the
50                          HECOX V. LITTLE


    Under the Act, anyone—be it a teammate, coach, parent,
or a member of an opposing team—may “dispute” a player’s
“biological sex,” requiring that player to visit her “personal
health care provider . . . [who will] verify the student’s
biological sex” through the player’s “reproductive anatomy,
genetic makeup, or normal endogenously produced
testosterone levels.” 

(3). The Act’s
express terms limit the verification procedure to a “routine
sports physical examination” by “relying only on one (1) or
more of the following: the student’s reproductive anatomy,
genetic makeup, or normal endogenously produced
testosterone levels.” 

 (emphasis added). By its plain text,
the Act provides that a student’s sex can be verified
exclusively by these three enumerated methods. Thus, the
district court was not unreasonable in finding incredulous


parties have stipulated is now moot. However, Lindsay brought the same
constitutional challenges to the sex dispute verification provision as Jane
did in her complaint, and argued in her motion for preliminary injunction
that she also would be subjected to the sex dispute verification process.
Indeed, Appellants recognized that Lindsay challenged the sex dispute
verification provision when they argued in front of the district court that
“Lindsay [could not] establish an injury in fact because the State Board
of Education ha[d] not yet promulgated regulations governing third-
party sex verification disputes,” Hecox, 469 F. Supp. 3d at 962, and that
Lindsay would not have to go through the sex dispute process because
her “health care provider [could] simply sign[] an ‘other statement’
stating that Lindsay is female.” Id. at 964.
  The district court reviewed these arguments and concluded that
Lindsay had standing to challenge the sex dispute verification provision,
because “it is not speculative to suggest Lindsay’s sex would be
disputed.” Id. at 961. The court then held that the sex dispute
verification provision likely did not survive heightened scrutiny because
of the “injury and indignity inflicted on Jane and all other female
athletes,” which includes Lindsay. Id. at 987. Thus, we decline to
dismiss the challenge to the sex dispute verification provision.
                       HECOX V. LITTLE                     51


defense counsel’s argument that the Act merely required
Lindsay to obtain a letter from her doctor stating that
Lindsay “is female.” Hecox, 469 F. Supp. 3d at 983. If that
was all that was required to verify a student’s sex under the
Act, Lindsay could simply obtain such a statement and the
Act (and this appeal) would be rendered meaningless.
    Any one of the three exclusive procedures requires far
more than a “routine sports physical” exam or simply asking
whether a patient is female or not. As Lindsay’s medical
expert Dr. Sara Swobada described, analyzing a student’s
“genetic makeup” would require referral to a “pediatric
endocrinologist” who would conduct a “chromosomal
microarray” that would reveal a “range of genetic
conditions” beyond sex chromosomes. Hormone testing
would also require a “pediatric endocrinologist,” and is not
a “routine part of any medical evaluation.” Of course, the
expense and burden of these tests would be borne only by
female students and their families.
    Requiring a student to find a medical practitioner to
examine their reproductive anatomy, which is what a typical
gynecological exam entails, is unconscionably invasive,
with the potential to traumatize young girls and women. As
Dr. Swobada opined, examining a female patient’s
“reproductive anatomy” would necessitate inspecting a
student athlete’s genitalia and conducting a pelvic
examination or transvaginal ultrasound to determine
whether that student has ovaries. She further explained that
pelvic examinations for young patients are generally not
required for minors, including adolescents, and are only
conducted when medically necessary “with sedation and
appropriate comfort measures to limit psychological
trauma.” Yet the Act’s sex verification process subjects girls
as young as elementary schoolers to unnecessary
52                          HECOX V. LITTLE


gynecological examinations merely because an individual
“disputes” their sex.
     The psychological burden of these searches does not just
fall on transgender women like Lindsay, but on all women
and girls. As amici describe, “[s]ex verification procedures
have a long, checkered history in female sports that continue
to this day.” Br. of Amici Curiae National Women’s Law
Center, et al. at 15. In the 1960s, the IOC would force female
athletes to strip and parade in front of a panel of doctors to
prove that they were, in fact, women. Id. The process was
discontinued after a public outcry. Id. One intersex athlete
who failed a sex verification procedure described being “so
‘tormented’ and ‘unbearably embarrassed’ that ‘she
attempted suicide’ by ‘swallowing poison.’” Id. at 17
(quoting Ruth Padawer, The Humiliating Practice of Sex-
Testing Female Athletes, N.Y. Times Magazine (June 28,
2016)). Tellingly, while many athletic organizations have
tightened their rules for transgender women’s competition
since 2020, none appears to have instituted a process that
required gynecological examinations or invasive physical
examinations. 18 Of the twenty other states that have passed
restrictions on transgender women’s participation in
women’s sports, none has authorized a similar sex
verification process. 19


18
    The IOC has expressly disavowed invasive sex verification
procedures, stating that “[c]riteria to determine eligibility for a gender
category should not include gynecological examinations or similar forms
of invasive physical examinations, aimed at determining an athlete’s sex,
sex variations or gender.” See Int’l Olympic 

.
19
   Most states that have instituted categorical bans on transgender
participation in student athletics have verified sex via a student’s birth
certificate. Oklahoma and Kentucky require a student or a student’s
                            HECOX V. LITTLE                             53


    Idaho has not offered any “exceedingly persuasive
justification” warranting the imposition of this objectively
degrading and disturbing process on young women and girls.
Before the Act’s passage, Idaho had no sex verification
process in place and nonetheless separated teams by gender.
The record is devoid of evidence that any boy attempted to
join a girls’ team. By the plain text of the Act, the purpose
of the sex verification process is to identify and exclude
transgender women and girls from women’s athletics in
Idaho. And a “bare . . . desire to harm a politically unpopular
group cannot constitute a legitimate governmental interest.”
Romer v. Evans, 

 (1996) (alteration in
original) (citation omitted).
    We agree with the district court that, contrary to the Act’s
express purpose of ensuring women’s equality and
opportunities in sports, the sex dispute verification process
likely will discourage the participation of Idaho female
students in student athletics by allowing any person to
dispute their gender and then subjecting them to unnecessary
medical testing and genital inspections. Because the Act’s
means undermine its purported objectives and impose an
unjustifiable burden on all female athletes in Idaho, the
district court did not abuse its discretion by finding that the
sex verification provision likely would not survive
heightened scrutiny.
                     B.        Irreparable Harm
    The district court properly concluded that Lindsay faced
irreparable harm absent an injunction. “It is well established


parent or legal guardian submit sworn affidavits to confirm their
“biological sex.” See 

(D); 

(2).
54                     HECOX V. LITTLE


that the deprivation of constitutional rights unquestionably
constitutes irreparable injury.” Hernandez v. Sessions, 

 (9th Cir. 2017) (internal quotation marks and
citation omitted).      Therefore, as the Act is likely
unconstitutional, “it follows inexorably . . . that [Hecox]
ha[s] [] carried [her] burden as to irreparable harm.” 

.
    More concretely, if the preliminary injunction is lifted,
Lindsay will be barred from trying out for or participating on
any female sports teams at BSU, including the women’s club
soccer team, which she joined to improve her running skills
and to experience “the camaraderie of being on a team.” See

(3). While Lindsay did not make the
track team in Fall 2020, the Act would bar her from trying
out for the team in Fall 2023, her last opportunity to play
NCAA sports. Lindsay would also be subject to the threat
of the sex dispute verification process and unnecessary
examinations or medical testing. These are all specific
“harm[s] for which there is no adequate legal remedy” in the
absence of an injunction. Ariz. Dream Act Coal. v. Brewer,

 (9th Cir. 2014).
     C.      Balance of the Equities & Public Interest
    The district court also did not err in concluding that the
balance of the equities weighed in favor of a preliminary
injunction. When the government is a party to a lawsuit, the
balance of the equities and public interest prongs of the
preliminary injunction test merge, because government
actions presumably are in the public interest. See Drakes
Bay Oyster Co., 

; Nken v. Holder, 

 (2009) (holding that “courts must be mindful that
the Government’s role as the respondent in every removal
proceeding does not make the public interest in each
                       HECOX V. LITTLE                      55


individual one negligible”). Here, Lindsay faces deeply
personal, irreparable harms without injunctive relief,
including being barred from all female college athletic teams
and the prospect of invasive medical testing if her gender is
“disputed.”
    A preliminary injunction does not appear to inflict any
comparable harm to the Appellants, as the injunction
expressly maintained the status quo. Under the status quo,
the NCAA policies for college athletics and the IHSAA
policies for high school athletics govern transgender female
participation in sports, and Idaho schools have complied
with those policies for over a decade. The district court
found no “evidence that transgender women threatened
equality in sports, girls’ athletic opportunities, or girls’
access to scholarships in Idaho” during that decade, and thus
Appellants failed to demonstrate any harm from issuance of
the injunction. Hecox, 469 F. Supp. 3d at 988. Moreover, as
the district court found, Intervenors themselves may also be
harmed by the sex dispute verification process, to which they
are subject simply by virtue of playing sports in Idaho.
Because “the public interest and the balance of the equities
favor preven[ting] the violation of a party’s constitutional
rights,” Ariz. Dream Act, 

 (alteration in
original) (internal quotation marks and citation omitted), we
affirm that the district court did not abuse its discretion in
weighing this factor.
           IV. SCOPE OF THE INJUNCTION
    Finally, we reject Intervenors’ argument that the scope of
the injunction is improper as a matter of law. “A district
court has considerable discretion in fashioning suitable relief
and defining the terms of an injunction,” and “[a]ppellate
review of those terms ‘is correspondingly narrow.’” Lamb-
56                          HECOX V. LITTLE


Weston, Inc. v. McCain Foods, Ltd., 

 (9th
Cir. 1991) (quoting Coca–Cola Co. v. Overland, Inc., 

, 1256 n.16 (9th Cir. 1982)). However, injunctive
relief “must be tailored to remedy the specific harm alleged,”
and “[a]n overbroad injunction is an abuse of discretion.” 

(finding that a worldwide injunction to protect a trade secret
was not an abuse of discretion). Under Federal Rule of Civil
Procedure Rule 65(d), “[e]very order granting an injunction
. . . must: (A) state the reasons why it issued; (B) state its
terms specifically; and (C) describe in reasonable detail—
and not by referring to the complaint or other document—
the act or acts restrained or required.”            However,
“injunctions are not set aside under [R]ule 65(d) [] unless
they are so vague that they have no reasonably specific
meaning.” United States v. Holtzman, 

 (9th
Cir. 1985).
    Here, the scope of the injunction is clear: The district
court enjoined the enforcement of any of the provisions of
the Act. 20 The district court explicitly held that the
injunction would restore the pre-Act status quo, such that the
“NCAA policy for college athletes and IHSAA policy for
high school athletes” would remain in effect. Hecox, 479 F.
Supp. 3d at 988. Nor did the district court abuse its
discretion as to the scope of the injunction. It concluded that

20
  The partial concurrence states that it is unclear whether the Court was
“enjoining all provisions of the Act or only some of them.” Partial
Concurrence at 81. However, the district court granted the motion for
preliminary injunction in full, see Hecox, 479 F. Supp. 3d at 989, and the
motion asked the district court to enjoin “enforc[ement of] any of the
provisions of” the Act. It does not appear from the record that either
party argued that the injunction should apply to only certain provisions
of the Act. Thus, no genuine confusion exists regarding whether the
entirety of the Act is enjoined.
                            HECOX V. LITTLE                              57


the Act was likely “unconstitutional as currently written,”
id., and properly enjoined enforcement of the Act in its
entirety. 21 That Lindsay’s case involves an as-applied

21
   The partial concurrence argues that we should remand this case to the
district court to tailor the injunction to provide the specificity that Rule
65(d)(1) requires because it is unclear whether the injunction is limited
to “transgender women and girls who either have never undergone
puberty or have suppressed their testosterone levels through hormone
therapy.” Partial Concurrence at 82. The concurrence also suggests that
the scope of the injunction is overbroad because it might “appl[y] to
transgender female athletes” who have gone through puberty and have
not received hormone therapy. Id. at 83. However, the district court
explicitly preserved the “status quo” in Idaho when fashioning the
injunction, stating:
       [A] preliminary injunction would not harm Defendants
       because it would merely maintain the status quo while
       Plaintiffs pursue their claims. If an injunction is issued,
       Defendants can continue to rely on the NCAA policy for
       college athletes and IHSSA policy for high school athletes, as
       they did for nearly a decade prior to the Act . . . [N]either
       Defendants nor the Intervenors would be harmed by returning
       to this status quo.
Hecox, 479 F. Supp. 3d at 988. At the time of the injunction, both
policies allowed transgender women and girls “to compete on girls’
teams after completing one year of hormone therapy suppressing
testosterone under the care of a physician.” Id. at 947. Thus, the district
court specifically stated how the injunction would apply to transgender
female athletes who have gone through puberty and not received
hormone therapy: those individuals would be required to conform to
current NCAA and IHSSA policies circumscribing the extent of their
participation in female athletics.
   In any event, there is no evidence that Idaho believes the terms of the
injunction “have no reasonably specific meaning.” Holtzman, 

. To the contrary, only Intervenors, not Idaho, argued on appeal
that the injunction was vague and overbroad, indicating that Idaho school
administrators have clearly understood over the past three years what
conduct is permissible under the injunction.
58                           HECOX V. LITTLE


challenge does not undermine the district court’s findings
that the Act is unconstitutional as applied to all women. See,
e.g., John Doe No. 1 v. Reed, 

 (2010)
(holding that a challenge to a category of applications of a
statute may be characterized as an as-applied challenge). 22
                                     V.
    While we address only the Act before us, and opine on
no other regulation or policy, we must observe that both the
science and the regulatory framework surrounding issues of
transgender women’s participation in female-designated
sports is rapidly evolving. Since Lindsay filed her initial
challenge, the IOC and NCAA have adopted more limited
policies as to transgender female participation in women’s
sports, requiring the governing entities for each sport to
formulate sport-specific policies. Relying on medical

22
   Intervenors, but not Idaho, contend that the injunction is overbroad
because it extends to non-plaintiffs in light of the district court’s
dismissal of Lindsay’s facial challenge. However, in Doe, the Supreme
Court explained that an as-applied claim could be “‘facial’ in that it is
not limited to plaintiffs’ particular case, but challenges application of the
law more broadly.” Doe, 

. Because the district court
found that the Act harmed “the constitutional rights of every girl and
woman athlete in Idaho,” Hecox, at 479 F. Supp. 3d at 988, it did not
abuse its discretion in issuing a preliminary injunction against the entire
category of applications of the Act.
   In addition, as the partial concurrence persuasively argues, the district
court could not accord Lindsay full relief without enjoining the Act in its
entirety consistent with the principle that “an injunction ‘should be no
more burdensome to the defendant than necessary to provide complete
relief to the plaintiffs before the court.’” City & County of San Francisco
v. Barr, 

 (9th Cir. 2020) (quoting L.A. Haven Hospice,
Inc. v. Sebelius, 

 (9th Cir. 2011)); see also E. Bay
Sanctuary Covenant v. Biden, 

 (9th Cir. 2021) (en
banc); Doe #1 v. Trump, 

 (9th Cir. 2020).
                           HECOX V. LITTLE                            59


evidence, many sports organizations have tightened their
eligibility criteria for transgender women’s teams, including
incorporating guidelines for lower testosterone levels for
eligibility to compete. 23 The U.S. Department of Education
has proposed new Title IX regulations addressing
restrictions on transgender athletes’ eligibility that would
require “such criteria” to “be substantially related to the
achievement of an important educational objective and
minimize harms to students whose opportunity to participate
on a male or female team consistent with their gender
identity would be limited or denied.” 24 These more narrowly
drawn policies, which are not before us, attempt to balance
transgender inclusion with competitive fairness—a policy
question that such regulatory bodies are best equipped to
address.




23
   See, e.g., USA Swimming, USA Swimming Releases Athlete Inclusion,
Competitive Equity and Eligibility Policy (Feb. 1, 2022),
https://tinyurl.com/mr2k4tvp (announcing a policy for USA Swimming
that elite transgender women athletes must show testosterone levels
below 5 nmol/L continuously for at least 36 months); Bicycling, The UCI
Announces Changes to Its Policy on Transgender Athletes (June 17,
2022),      https://www.bicycling.com/news/a40320907/uci-transgender-
policy-2022/ (announcing a testosterone limit of 2.5 nmol/L for elite
bicyclists (halved from the previous 5.0 nmol/L) for a suppression period
of 24 months); Olalla Cernuda, World Triathlon Executive Board
approves Transgender Policy, World Triathlon (Aug. 3, 2022),
https://tinyurl.com/yxw4syzw (requiring below a 2.5 nmol/L
testosterone level for 24 months for triathletes).
24
   Nondiscrimination on the Basis of Sex in Education Programs or
Activities Receiving Federal Financial Assistance: Sex-Related
Eligibility Criteria for Male and Female Athletic Teams, 

 (proposed April 13, 2023) (to be codified at 34 C.F.R. pt. 106).
60                      HECOX V. LITTLE


                     VI. CONCLUSION
    We recognize that, after decades of women being denied
opportunities to meaningfully participate in athletics in this
country, many cisgender women athletes reasonably fear
being shut out of competition because of transgender athletes
who “retain an insurmountable athletic advantage over
cisgender women.” See Br. of Amici Curiae Sandra Bucha,
et al. at 8. We also recognize that athletic participation
confers to students not just an opportunity to win
championships and scholarships, but also the benefits of
shared community, teamwork, leadership, and discipline.
See generally Br. of Amici Curiae 176 Athletes in Women’s
Sports (describing the benefits of sports, and diversity in
women’s sports, on all students). Excluding transgender
youth from sports necessarily means that some transgender
youth will be denied those educational benefits.
    However, we need not and do not decide the larger
question of whether any restriction on transgender
participation in sports violates equal protection. Heightened
scrutiny analysis is an extraordinarily fact-bound test, and
today we simply decide the narrow question of whether the
district court, on the record before it, abused its discretion in
finding that Lindsay was likely to succeed on the merits of
her equal protection claim. Because it did not, we affirm the
entry of preliminary injunctive relief against the Act’s
enforcement.
     AFFIRMED.
                       HECOX V. LITTLE                     61


CHRISTEN, Circuit Judge, concurring in part and
dissenting in part:
    The Fairness in Women’s Sports Act, 2020 Idaho Sess.
Laws 967–70 (codified at 

-6201⁠–06) (the
“Act”), declares that “[a]thletic teams or sports designated
for females, women, or girls shall not be open to students of
the male sex.” 

(2). The Act considers
transgender women and girls to be “students of the male
sex.” Accordingly, the Act bans all transgender women and
girls from competing in school sports in Idaho on teams that
are consistent with their gender identities. The ban applies
broadly to all public schools, from kindergarten through
college, and to all private schools and colleges whose
students or teams compete against public schools or
colleges. 

 § 33-6203(1). The ban also applies to all kinds
of sports, to all grades and ages, and to all types of
competition. And the ban extends to all transgender women
and girls, including those who are too young to have
experienced puberty, those whose use of puberty blockers
prevented them from ever going through puberty, and those
who have undergone a year or more of hormone therapy to
suppress their levels of circulating testosterone. To enforce
the ban, the Act permits any individual to “dispute” the sex
of any athlete participating in women’s or girls’ sports. Id.
§ 33-6203(3). If a student’s sex is disputed, the statute
requires the student to have her health care provider “verify”
her “biological sex.” Id. To provide the necessary
verification, the health care provider may rely “only on one
(1) or more of the following: the student’s reproductive
anatomy, genetic makeup, or normal endogenously produced
testosterone levels.” Id.
   Lindsay Hecox, a student at Boise State University who
wants to participate in her college’s women’s track team,
62                      HECOX V. LITTLE


claims that the Act violates her statutory and constitutional
rights, including her Fourteenth Amendment right to equal
protection of the laws. Lindsay is a transgender woman who
undergoes gender-affirming hormone therapy that reduces
her testosterone levels. She would have been eligible to
participate in women’s sports in Idaho under the policies in
place before the Act was adopted, but she is prevented from
doing so under the Act.
     In August 2020, the district court granted Lindsay’s
motion to preliminarily enjoin enforcement of the Act
pending trial on the merits of her claims. The court entered
extensive findings and ruled that Lindsay was likely to
succeed on her equal protection claim. Hecox v. Little
(Hecox I), 

 (D. Idaho 2020). In doing
so, the court reasoned that the Act is not substantially related
to the State’s important interests in promoting sex equality
and providing athletic opportunities for women, because the
Act bans transgender women and girls categorically, rather
than focusing on those transgender women and girls who, by
virtue of their testosterone levels, have real athletic
advantages over other women and girls. The court also
reasoned that the Act’s dispute and sex verification provision
was likely to hinder, rather than further, the State’s important
interests “by subjecting women and girls to unequal
treatment, excluding some from participating in sports at all,
incentivizing harassment and exclusionary behavior, and
authorizing invasive bodily examinations.” 

.
     Like the majority, I conclude that the district court did
not abuse its discretion by granting preliminary injunctive
relief. The district court carefully considered the evidence
and made findings amply supported by the record. Given
our limited and deferential review at this stage of the
litigation, the categorical sweep of the ban on transgender
                         HECOX V. LITTLE                       63


students, the medical consensus that circulating testosterone
rather than transgender status is an accurate proxy for
athletic performance, and the unusual and extreme nature of
the Act’s sex verification requirements, the district court did
not abuse its discretion by concluding that Lindsay was
likely to succeed on her equal protection claim.
    I also agree with the majority that the district court did
not abuse its discretion by enjoining enforcement of the
statute against non-plaintiffs. Given the partially facial
nature of Lindsay’s claims and the Supreme Court’s
discussion of this subject in John Doe No. 1 v. Reed, 

 (2010), I conclude that the district court acted
within its broad discretion.
    Although I agree with much of the majority opinion, I
respectfully disagree with the majority in certain respects.
First, I disagree with the majority’s conclusion that “only
women and girls who want to compete on Idaho school
athletic teams, and not male athletes, are subject to the sex
dispute verification process.” Maj. Op. at 36. I read the
verification provision to apply to any student, male or
female, who participates on women’s or girls’ athletic teams.
The verification provision does not apply to any student,
male or female, who participates on men’s or boys’ athletic
teams. Accordingly, I conclude that it is the team an athlete
chooses to join that dictates whether they are subject to the
statute’s verification process, not the athlete’s sex. In my
view, the majority errs in holding otherwise.
    Second, I disagree with the majority’s conclusion that the
preliminary injunction satisfies the specificity requirements
set out in Federal Rule of Civil Procedure 65(d)(1). The
injunction does not “state its terms specifically” or “describe
in reasonable detail . . . the . . . acts restrained or required.”
64                      HECOX V. LITTLE


     Finally, I disagree with the majority’s conclusion that the
district court properly “tailor[ed] the scope of the remedy to
fit the nature and extent of the constitutional violation.” City
& County of San Francisco v. Trump, 

(9th Cir. 2018) (quoting Hills v. Gautreaux, 

,
293–94 (1976)). The district court appears to have enjoined
§ 33-6203(2) as applied to all transgender female athletes.
But the court made no findings suggesting that § 33-6203(2)
is unconstitutional as applied to transgender women and girls
who have gone through puberty and have not received
hormone therapy to suppress testosterone. Given the court’s
finding that the medical consensus treats circulating
testosterone as the key factor in determining differences in
athletic performance, the injunction is not appropriately
tailored.
    For these reasons, I would affirm the district court’s
order in part, vacate it in part, and remand. I therefore concur
in part, and respectfully dissent in part, from the court’s
judgment.
                I. Interpreting § 33-6203(3)
    Although the majority does not directly address the
issue, I note that the parties interpret the Act’s sex
verification provision differently. 

(3)
states:

       A dispute regarding a student’s sex shall be
       resolved by the school or institution by
       requesting that the student provide a health
       examination and consent form or other
       statement signed by the student’s personal
       health care provider that shall verify the
       student’s biological sex. The health care
                        HECOX V. LITTLE                    65


       provider may verify the student’s biological
       sex as part of a routine sports physical
       examination relying only on one (1) or more
       of the following: the student’s reproductive
       anatomy, genetic makeup, or normal
       endogenously produced testosterone levels.

 (emphasis added).
    Appellants assert that a health care provider may verify
a student’s biological sex through any means, not only
through the three means enumerated in the statute
(reproductive anatomy, genetic makeup, and normal
endogenously produced testosterone levels). The State
argues:

       The statute provides three separate options to
       verify sex. The first two options, (1) a health
       examination and consent form or (2) other
       statement signed by the student’s personal
       health care provider, are not subject to the
       three criteria mentioned in the third option,
       the “routine sports physical examination.”
       They are different means, and listed in a
       completely different sentence. Moreover, the
       separate, third option, a “routine sports
       physical examination,” makes clear that it is
       permissive, not required, using the term
       “may.”

State’s Opening Brief at 38. Lindsay, by contrast, argues that
because the statute specifies that providers may rely “only
on one (1) or more of the following,” it plainly limits health
66                      HECOX V. LITTLE


care providers to using one of the three means enumerated
in the statute.
     I agree with Lindsay. Boiled down, the State interprets
the statute to mean that a health care provider may verify a
student’s sex by: (1) a routine sports physical examination
relying on one or more of the enumerated means; or (2) any
“other statement” relying on any means at all. The State’s
reading sharply diverges from the language adopted by the
legislature and renders the provision’s second sentence
inoperative. The State argues that the district court failed to
apply Idaho’s principles of statutory interpretation, see
State’s Opening Brief at 37, but notably fails to identify any
support for its anti-textual interpretation, from Idaho or
elsewhere. Because the second sentence becomes a dead
letter under the State’s interpretation, the statute is not
reasonably susceptible to the interpretation offered by the
State. See State v. Yzaguirre, 

 (Idaho
2007) (“In interpreting statutory language, all the words of
the statute must be given effect if possible, and the statute
must be construed as a whole.”).
     II. Intermediate Scrutiny Applies Because the Act
         Discriminates Based on Transgender Status
    I agree with the majority, and with the district court, that
intermediate scrutiny applies.
    Before the passage of the Act, Idaho prohibited “men and
boys” from participating on teams designated for women and
girls. As the district court pointed out, “general sex
separation on athletic teams for men and women . . .
preexisted the Act and has long been the status quo in Idaho.
Existing rules already prevented boys from playing on girls’
teams before the Act.” Hecox I, 479 F. Supp. 3d at 982.
However, Idaho’s pre-Act status quo allowed transgender
                           HECOX V. LITTLE                            67


women and girls (i.e., athletes assigned male at birth who
identify as female) to participate in women’s and girls’ sports
consistent with Idaho High School Activities Association
(IHSAA) and National Collegiate Athletic Association
(NCAA) policies. To be eligible, these students had to
provide proof that they had undergone at least one year of
hormone therapy to suppress their testosterone levels.
Hence, although the Act is couched in terms that suggest it
classifies student athletes according to their “biological sex,”

(1), (3), and purports to preclude
students of the “male sex” from participating in women’s
and girls’ sports, the ban in fact serves only to prohibit
transgender women and girls from women’s and girls’ sports
teams. The ban’s exclusive function is to abrogate the
IHSAA and NCAA policies allowing transgender women
and girls, under limited circumstances, to participate in
women’s and girls’ sports. 1
    Under these circumstances, that the Act speaks in terms
of “biological sex,” rather than “transgender status” or
“gender identity,” is not controlling. The Act changed the
status quo by classifying athletes, for the first time, based on
transgender status. The conclusion that the Act classifies
based on transgender status finds extensive support in

1
  The principal section of the statute, 

, comprises
three subsections. They are all integral parts of the statutory plan to
exclude transgender women and girls from women’s and girls’ sports.
Section 33-6203(2) effects a ban, or prohibition, on transgender athletes
participating in sports designated for women or girls. Section 33-
6203(3), the sex verification provision, is the enforcement mechanism
for the ban. Section 33-6203(2) operates exclusively against transgender
female athletes for the reasons explained in the text. But any student—
male or female, transgender or cisgender—who participates in sports
designated for women or girls is subject to the verification provision in
§ 33-6203(3)).
68                        HECOX V. LITTLE


controlling case law. In Personnel Administrator of
Massachusetts v. Feeney, 

 (1979), the Supreme
Court recognized that a statute may classify covertly as well
as overtly:

        When a statute gender-neutral on its face is
        challenged on the ground that its effects upon
        women are disproportionably adverse, a
        twofold inquiry is thus appropriate. The first
        question     is    whether the statutory
        classification is indeed neutral in the sense
        that it is not gender-based.           If the
        classification itself, covert or overt, is not
        based upon gender, the second question is
        whether the adverse effect reflects invidious
        gender-based discrimination.

. Under Feeney, a statute that is gender-neutral on
its face nevertheless classifies based on gender if the
statutory classification “can plausibly be explained only as a
gender-based classification.” 

. 2 In Latta v. Otter,

 (9th Cir. 2014), for example, we held that laws
defining marriage as a relationship “between a man and a
woman,” 

 at 464 n.2, but making no mention of sexual
orientation, nevertheless “distinguish[ed] on their face
between opposite-sex couples, who are permitted to marry
and whose out-of-state marriages are recognized, and same-
sex couples, who are not permitted to marry and whose


2
  I do not conclude that the ban is a transgender-based classification
because it has a disproportionate adverse impact on transgender women
and girls. The Supreme Court has made clear that disproportionate
impact alone does not trigger heightened scrutiny under the Equal
Protection Clause. See Washington v. Davis, 

 (1976).
                       HECOX V. LITTLE                     69


marriages are not recognized.” Id. at 467. The defendants
could not “overcome the inescapable conclusion” that the
laws “discriminate[d] on the basis of sexual orientation.” Id.
at 468. We applied the same reasoning in Pacific Shores
Properties, LLC v. City of Newport Beach, 

(9th Cir. 2013), a Fair Housing Act case, where we
explained:

       Proxy discrimination is a form of facial
       discrimination. It arises when the defendant
       enacts a law or policy that treats individuals
       differently on the basis of seemingly neutral
       criteria that are so closely associated with the
       disfavored group that discrimination on the
       basis of such criteria is, constructively, facial
       discrimination against the disfavored group.
       For example, discriminating against
       individuals with gray hair is a proxy for age
       discrimination because “the ‘fit’ between age
       and gray hair is sufficiently close.”
       McWright v. Alexander, 

       (7th Cir. 1992).

 at 1160 n.23; cf. Bray v. Alexandria Women’s Health
Clinic, 

 (1993) (

(3)) (“A
tax on wearing yarmulkes is a tax on Jews.”); McWright, 

 (Rehabilitation Act) (“We have warned that an
employer cannot be permitted to use a technically neutral
classification as a proxy to evade the prohibition of
intentional discrimination.”).
    Given the Act’s context, these authorities support the
conclusion that the Act classifies based on transgender
status. As in Feeney, the Act can only be understood as a
70                           HECOX V. LITTLE


transgender-based classification. As in Latta, the Act
distinguishes on its face between cisgender women and girls,
who can compete on teams consistent with their gender
identity, and transgender women and girls, who are
categorically barred from doing so. The Act “use[s] a
technically neutral classification”—biological sex—“as a
proxy to evade the prohibition of intentional
discrimination.” McWright, 

. Indeed,
transgender women and girls are the only students who are
actually affected by the Act’s classification; they are the only
group banned from participating on athletic teams that are
aligned with their gender identities. 3

3
  Under the Act, cisgender men and boys may participate on men’s and
boys’ teams and may do so without being subject to the sex verification
procedure. So can transgender men and boys. Cisgender women may
participate on athletic teams designated for women and girls, though like
all athletes on these teams, they are subject to the sex verification
procedure that serves as the Act’s enforcement mechanism. Transgender
women and girls are uniquely disadvantaged under the Act:
                       Allowed           to     Subject           to
                       Participate on Team      Verification
                       Aligned with Gender      Provision if Playing
                       Identity                 on Team Aligned
                                                with Gender Identity

    Cisgender men      Yes                      No
    and boys
    Transgender men    Yes                      No
    and boys
    Cisgender          Yes                      Yes*
    women and girls
    Transgender        No*                      Yes*
    women and girls
An asterisk (*) indicates a change from the policies in place before the
Act’s passage.
                       HECOX V. LITTLE                      71


     Furthermore, even putting Feeney, Latta, and Pacific
Shores aside, no one disputes that heightened scrutiny
applies “[w]hen there is a proof that a discriminatory
purpose has been a motivating factor in the decision.”
Village of Arlington Heights v. Metro. Hous. Dev. Corp., 

, 265–66 (1977). A discriminatory purpose is
shown when “the decisionmaker, in this case a state
legislature, selected or reaffirmed a particular course of
action at least in part ‘because of,’ not merely ‘in spite of,’
its adverse effects upon an identifiable group.” Feeney, 

.
    These principles map perfectly onto Lindsay’s challenge
because the Act purposefully treats transgender women and
girls differently from every other group. The district court
found that “the law is directed at excluding women and girls
who are transgender, rather than on promoting sex equality
and opportunities for women.” Hecox I, 479 F. Supp. 3d at
983. This finding is well supported. The court inferred a
discriminatory purpose from the fact that the Act bars
transgender athletes categorically rather than focusing on
factors—such as puberty and circulating testosterone—that
a consensus of the medical community actually associates
with athletic performance. The district court noted that the
Act’s definition of “biological sex”:

       excludes the one factor that a consensus of
       the medical community appears to agree
       drives the physiological differences between
       male and female athletic performance.
       Significantly, the preexisting Idaho and
       current NCAA rules instead focus on that
       factor.    That the Act essentially bars
       consideration of circulating testosterone
72                      HECOX V. LITTLE


       illustrates the Legislature appeared less
       concerned with ensuring equality in athletics
       than it was with ensuring exclusion of
       transgender women athletes.

Id. at 984. The district court’s findings are not clearly
erroneous.       Indeed, the Act’s legislative sponsor,
Representative Barbara Ehardt, forthrightly acknowledged
that the legislature’s purpose in enacting the statute was to
force transgender women and girls “to compete on the side
of those biological boys and men . . . whom they look alike.”
This unvarnished record and the district court’s cogent
recognition of the real change effected by the Act in Idaho
lend strong support for the district court’s conclusion that the
Act classifies based on transgender status and discriminates
against transgender women and girls.
    I agree with the district court, and with the majority, that
intermediate scrutiny applies because the Act classifies and
discriminates on account of transgender status.
III. The Verification Provision Does Not Apply Only to
                    Female Students
    I part company, however, with the majority’s conclusion
that “only women and girls who want to compete on Idaho
school athletic teams, and not male athletes, are subject to
the sex dispute verification process.” Maj. Op. at 36.
   On its face, the sex verification provision is applicable to
any student, male or female, participating on “[a]thletic
teams or sports designated for females, women, or girls.”
See 

(2). By its terms, the verification
process applies to men and boys who wish to participate on
teams designated for women and girls, and it does not apply
to athletes of any gender who participate on teams
                            HECOX V. LITTLE                            73


designated for men or boys. It is the team an athlete chooses
to join that dictates whether they are subject to the statute’s
verification process, not the athlete’s sex. 4
    The majority’s approach and my own differ somewhat,
but we agree that the Act fails to satisfy heightened scrutiny.
The majority analyzes the verification provision in isolation,
decides that heightened scrutiny applies because the
provision does not apply to males (a proposition with which
I respectfully disagree), and then holds that the district court
did not abuse its discretion in concluding that Lindsay is
likely to succeed on her claim that the verification provision
is not substantially related to Idaho’s important
governmental interests. By contrast, I see no need to analyze
the verification provision in isolation. In my view, the
verification provision is an integral part of the ban on
transgender women and girls participating on women’s and
girls’ teams. It is the critical mechanism by which the ban is
implemented and enforced. Thus, I would simply address
whether the ban as a whole survives heightened scrutiny. As
explained, heightened scrutiny applies because the ban as a



4
  The verification process applies to both male and female students, as
long as they join, or try to join, teams designated for women or girls. It
applies to: (1) cisgender female students who play on women’s and girls’
teams, as the Act allows; (2) transgender female students who play on
women’s and girls’ teams, as the Act prohibits; (3) transgender male
students (i.e., students who are assigned female at birth but identify as
male) if they choose to play on women’s and girls’ teams, as the Act
permits; and (4) cisgender male students who play on women’s and girls’
teams, as the Act prohibits, or who, like the plaintiffs in the Clark
litigation discussed below, desire to do so. The verification procedure
does not apply to any students playing on teams designated for men or
boys.
74                     HECOX V. LITTLE


whole both classifies and discriminates based on transgender
status.
                IV. Clark Does Not Control
    I agree with the majority that our decision in Clark ex
rel. Clark v. Arizona Interscholastic Ass’n, 

(9th Cir. 1982), is not controlling here. In Clark, we upheld
an Arizona policy prohibiting boys from playing on girls’
volleyball teams because: (1) “boys’ overall [athletic]
opportunity [wa]s not inferior to girls’”; and (2) sex served
as an “accurate proxy” for “real . . . physiological
differences.” Clark, 

. We held that the
exclusion satisfied intermediate scrutiny because “[t]he
record makes clear that due to average physiological
differences, males would displace females to a substantial
extent if they were allowed to compete for positions on the
volleyball team,” and “athletic opportunities for women
would [thereby] be diminished.” 

    Appellants’ reliance on Clark is misplaced. First, the
only issue we decided in Clark—whether a sex-based
classification was constitutionally permissible—is not in
dispute here. The district court dismissed Plaintiffs’ facial
challenges to the Act, Hecox I, 479 F. Supp. 3d at 971, in
light of Clark and the State’s argument that the ban “can . . .
be constitutionally applied to cisgender boys,” id. at 969.
Idaho has long maintained separate teams and sports for
men/boys and women/girls. See id. at 982. Those
classifications, which for decades have been widely
understood as a constitutionally permissible means of
advancing equality for women and girls in sports, are not at
issue here. The question that is presented here—whether a
classification based on “biological sex” or transgender status
                            HECOX V. LITTLE                              75


is constitutionally permissible—is one that was not
presented in Clark.
    Second, the facts of this case have little in common with
Clark. The record in Clark made clear that sex was a valid
proxy for average physiological differences between men
and women. Here, by contrast, the district court found that
the ban on transgender female athletes applies broadly to
many students who do not have athletic advantages over
cisgender female athletes. In addition, as the district court
pointed out, “under the Act, women and girls who are
transgender will not be able to participate in any school
sports, unlike the boys in Clark, who generally had equal
athletic opportunities.” Id. at 977 (emphasis added). 5 In
sum, Idaho’s ban on transgender women and girls must rise
or fall on its own merits; Clark is legally and factually
distinguishable.




5
  See Hecox I, 479 F. Supp. 3d at 977 (“[T]he Act’s categorical exclusion
of transgender women and girls entirely eliminates their opportunity to
participate in school sports.”); see id. (noting that “forcing a transgender
woman to participate on a men’s team would be forcing her to be
cisgender, which is ‘associated with adverse mental health outcomes’”);
id. (“Participating in sports on teams that contradict one’s gender identity
‘is equivalent to gender identity conversion efforts, which every major
medical association has found to be dangerous and unethical.’”); Lindsay
Hecox decl. ¶ 37 (“I would not compete on a men’s team. I am not a
man, and it would be embarrassing and painful to be forced onto a team
for men—like constantly wearing a big sign that says ‘this person is not
a “real” woman.’ I would be an outcast on the men’s team.”).
76                      HECOX V. LITTLE


 V. The Act Is Not Substantially Related to the State’s
  Important Interests and the District Court Did Not
    Abuse Its Discretion by Granting Preliminary
                   Injunctive Relief
    It is undisputed that the State has articulated “important
governmental objectives” here: “promot[ing] sex equality”
in sports and “providing opportunities for female athletes to
demonstrate their skill, strength, and athletic abilities while
also providing them with opportunities to obtain recognition
and accolades, college scholarships, and the numerous other
long-term benefits that flow from success in athletic
endeavors.” 

(12). Under intermediate
scrutiny, the operative question is simply whether “the
discriminatory means employed [by the Act] are
substantially related to the achievement of those objectives.”
United States v. Virginia, 

 (1996) (quoting
Miss. Univ. for Women v. Hogan, 

 (1982)).
Given the district court’s extensive findings and our limited
and deferential review, I agree with the majority that the
district court did not abuse its discretion by concluding that
Lindsay is likely to succeed on her claim that the Act is not
substantially related to the State’s interests in promoting
equality and providing athletic opportunities, including
scholarships, for women.
    In large part, the district court concluded that the Act was
unrelated to the State’s important interests because it
excludes transgender women and girls from women’s sports,
purportedly in the interest of competitive fairness, but it
excludes them in ways that bear no relationship to
physiological advantages and athletic performance. After
reviewing the expert evidence presented by the parties, the
district court found that “the sex difference in circulating
testosterone of adults explains most, if not all, of the sex
                        HECOX V. LITTLE                      77


differences in sporting performance.” Hecox I, 479 F. Supp.
3d at 980. Appellants disagree with that finding, but on the
record presented to the district court at the preliminary
injunction stage, the finding was well supported, and it is not
clearly erroneous. Indeed, the district court drew this finding
from the defense expert, Dr. Brown’s, own report. See id.;
Brown decl. ¶ 81.
     Given the medical-community consensus regarding the
connection between circulating testosterone and athletic
performance, the district court reasonably rejected
Appellants’ contention that the Act’s categorical ban is
substantially related to the State’s interests in promoting
equality and providing athletic opportunities for women and
girls. The district court found that the ban’s broad sweep
extends to many transgender women and girls who do not
possess physiological advantages over cisgender women and
girls. The court noted, for instance, that the ban applies to
students who are too young to have experienced puberty.
The court found that these girls have no competitive
advantage, because, “[b]efore puberty, boys and girls have
the same levels of circulating testosterone.” Id. at 979.
These findings are not clearly erroneous. On the contrary,
they appear to be undisputed. See Brown decl. ¶ 113
(“[B]efore puberty, boys and girls do not differ in height,
muscle and bone mass.”), ¶ 114 (“This physical advantage
in performance arises during early adolescence when male
puberty commences after which men acquire larger muscle
mass and greater strength, larger and stronger bones, higher
circulating haemoglobin as well as mental and/or
psychological differences.”), ¶ 119 (“[G]ender divergences .
. . arise from the increase in circulating testosterone from the
start of male puberty.”); Safer decl. ¶ 38 (“Increased
testosterone begins to affect athletic performance at the
78                      HECOX V. LITTLE


beginning of puberty.”); Safer suppl. decl. ¶ 13 (“[B]efore
puberty there are not noticeable performance difference[s]
between boys and girls. . . . There is simply no basis for the
assertion that pre-pubertal children have physical sex-based
performance differences.”).
    The district court also noted that the Act applies to the
“population of transgender girls who, as a result of puberty
blockers at the start of puberty and gender affirming
hormone therapy afterward, never go through a typical male
puberty at all.” Hecox I, 479 F. Supp. 3d at 980. The court
found that these athletes too do “not have an ascertainable
advantage over cisgender female athletes.” Id. These
findings are not clearly erroneous, and they also appear to be
undisputed.      Plaintiffs’ expert, Dr. Safer, testified
consistently with the district court’s findings, see Safer decl.
¶¶ 47–49, and the defense expert, Dr. Brown, appears to
have offered no contrary opinion on this point. Although Dr.
Brown argued that transgender women and girls who have
gone through puberty have some enduring athletic
advantages, even if they later undergo hormone therapy, see
Brown decl. ¶¶ 11(c)–13, 126–53, 163(c), he did not
challenge Dr. Safer’s conclusions regarding women who are
administered puberty blockers at the start of puberty and
gender-affirming hormone therapy afterward.
    The district court also found that the Act is unrelated to
competitive fairness because it applies to women and girls
who, like Lindsay, have undergone hormone therapy and
testosterone suppression for twelve months or more. See
Hecox I, 479 F. Supp. 3d at 979–80. The parties’ experts
disagree about whether these women and girls have lasting
physiological advantages, but the district court’s findings are
well-grounded in the evidentiary record that was available to
the court. They are consistent with Dr. Safer’s opinion that
                        HECOX V. LITTLE                      79


“physiological advantages are not present when a
transgender woman undergoes hormone therapy and
testosterone suppression,” id. at 979; with the results of the
Harper study, which the parties appear to agree is “the only
study examining the effects of gender-affirming hormone
therapy on the athletic performance of transgender athletes,”
id. at 980; with the “medical consensus that the difference in
testosterone is generally the primary known driver of
differences in athletic performance between elite male
athletes and elite female athletes,” id.; with the findings of
the Handelsman study—cited by the defense’s own expert,
see Brown decl. ¶ 81—that the “evidence makes it highly
likely that the sex difference in circulating testosterone of
adults explains most, if not all, of the sex differences in
sporting performance,” Hecox I, 479 F. Supp. 3d at 980; and
with the IHSAA and NCAA policies that existed before the
Act’s adoption.
    The Act’s relationship to its stated purposes is also in
tension with its broad application to all sports. It applies not
only to elite or highly competitive sports but also to less
competitive grade school and club sports. It applies to all
ages and grades, and to all sports regardless of physicality,
risk of injury, or selectivity. Intermediate scrutiny does not
require narrow tailoring, but it does require “a substantial
relationship between the exclusion of [transgender athletes]
from the team and the goal of . . . providing equal
opportunities for women.” See Clark, 

.
Here, the district court reasonably concluded that the “fit”
between the Act’s means and ends is sorely lacking.
    Finally, the district court found that an integral
component of the ban—the State’s uniquely invasive dispute
and sex verification provision—was likely to hinder rather
than advance the Act’s stated interest in promoting athletic
80                      HECOX V. LITTLE


opportunities for women. The court found that subjecting
female athletes to bullying, harassment, and invasive
medical procedures is likely to have the perverse effect of
discouraging women from participating in scholastic sports,
a result directly contrary to the Act’s stated purpose. See
Hecox I, 479 F. Supp. 3d at 985–87. These findings are not
clearly erroneous.
    Given the district court’s extensive and well-supported
findings, I agree with the majority that the district court did
not abuse its discretion by concluding that Lindsay is likely
to succeed on her claim that the Act is not substantially
related to its purported goals of promoting sex equality,
providing opportunities for female athletes, or increasing
female athletes’ access to scholarships. Accordingly, the
district court did not abuse its discretion by concluding that
Lindsay is likely to succeed on the merits of her equal
protection claim.
    For the reasons given by the majority, I also agree that
the district court did not abuse its discretion by concluding
that the remaining preliminary injunction factors favored
relief. The majority correctly observes that where the State
is a party, the last two factors in the Winter test for
preliminary injunctive relief merge. I only add that the
public interest factor favors relief here because “all citizens
have a stake in upholding the Constitution,” Preminger v.
Principi, 

 (9th Cir. 2005), and “it is always
in the public interest to prevent the violation of a party’s
constitutional rights,” Melendres v. Arpaio, 

 (9th Cir. 2012) (citation omitted). In sum, I agree with
the majority that the district court did not abuse its discretion
by concluding that preliminary injunctive relief was
warranted.
                        HECOX V. LITTLE                      81


    VI. The Preliminary Injunction Is Insufficiently
                      Specific
    Intervenors also raise several procedural challenges to
the preliminary injunction. I conclude that some of them
have merit.
    Under Rule 65(d)(1) of the Federal Rules of Civil
Procedure, “[e]very order granting an injunction . . . must:
(A) state the reasons why it issued; (B) state its terms
specifically; and (C) describe in reasonable detail—and not
by referring to the complaint or other document—the act or
acts restrained or required.” “The Rule was designed to
prevent uncertainty and confusion on the part of those faced
with injunctive orders, and to avoid the possible founding of
a contempt citation on a decree too vague to be understood.”
Schmidt v. Lessard, 

 (1974) (per curiam).
In addition, “[u]nless the trial court carefully frames its
orders of injunctive relief, it is impossible for an appellate
tribunal to know precisely what it is reviewing.” 

.
“Injunctions are not set aside under rule 65(d), however,
unless they are so vague that they have no reasonably
specific meaning.” United States v. Holtzman, 

 (9th Cir. 1985).
    The majority deems the preliminary injunction
sufficiently specific because “[t]he district court enjoined the
enforcement of any of the provisions of the Act.” Maj. Op.
at 56. But the district court ruled only that “[t]he Motion for
Preliminary Injunction (Dkt. 22) is GRANTED.” Hecox I,
479 F. Supp. 3d at 989. The court did not specify whether it
was enjoining all provisions of the Act or only some of them,
or whether it was enjoining any specific provision of the Act
in its entirety or only as applied to certain classes of
individuals. The court’s findings could be understood as
82                         HECOX V. LITTLE


implying that the court intended to enjoin the Act’s ban
solely as to transgender women and girls who do not have
athletic advantages over other female athletes—i.e.,
transgender women and girls who either have never
undergone puberty or have suppressed their testosterone
levels through hormone therapy. Alternatively, the court’s
broad language could be read as enjoining the entire Act in
all respects, as the majority suggests.
    Even if it were clear that the district court intended to
enjoin the Act in its entirety, the injunction remains unclear
because it does not specify the eligibility rules applicable
while the Act is preliminarily enjoined. The majority asserts
that the injunction is sufficiently clear because it “explicitly
preserved” the NCAA and IHSAA rules in place “[a]t the
time of the injunction,” Maj. Op. at 57 n.21 (citing Hecox I,
479 F. Supp. 3d at 988), rules that “allowed transgender
women and girls ‘to compete on girls’ teams after
completing one year of hormone therapy suppressing
testosterone under the care of a physician,’” Maj. Op. at 57
n.21 (quoting Hecox I, 479 F. Supp. 3d at 947). If that was
the court’s intent, it did not say so, and as the parties
recognize in their briefs, the NCAA rules have changed
substantially since the district court granted the preliminary
injunction three years ago. 6 It is unclear whether the “status
quo” should be understood as the NCAA rules in place in
2020 or the NCAA rules in place today.
   Rather than subjecting school administrators to
uncertainty about the scope of the injunction, we should ask

6
  This appeal has been pending for nearly three years due to a backlog in
the district court’s docket arising from the COVID-19 pandemic and this
court’s limited remand—conditions that the district court could not have
anticipated at the time it granted the preliminary injunction.
                        HECOX V. LITTLE                      83


the district court to provide the specificity that Rule 65(d)(1)
requires.
    VII. On the Current Findings, the Injunction Is
   Overbroad to the Extent It Applies to Transgender
   Women Who Are Not Receiving Gender-Affirming
                  Hormone Therapy
    As discussed, there are no findings in the current record
to suggest that Lindsay is likely to succeed on her claim that
the ban is unconstitutional as applied to transgender female
athletes who have gone through puberty and are not
receiving gender-affirming hormone therapy. Accordingly,
if the injunction extends to these individuals, the district
court likely abused its discretion. See City & County of San
Francisco, 897 F.3d at 1244 (“Once a constitutional
violation is found, a federal court is required to tailor the
scope of the remedy to fit the nature and extent of the
constitutional violation.” (quoting Hills, 425 U.S. at 293–
94)); Lamb-Weston, Inc. v. McCain Foods, Ltd., 

 (9th Cir. 1991) (“Injunctive relief . . . must be
tailored to remedy the specific harm alleged.”). I would
vacate in part and remand for the district court to tailor the
scope of the remedy to the constitutional violation.
 VIII. The District Court Did Not Abuse Its Discretion
  by Enjoining Enforcement of the Act Against Non-
                       Plaintiffs
    Intervenors contend that the preliminary injunction is
overbroad because it bars enforcement of § 33-6203 against
non-plaintiffs. They argue that this relief was improper
because “the district court dismissed Plaintiffs’ facial
challenge and proceeded only on their as-applied claims.”
Intervenors’ Opening Brief at 59. In light of the Supreme
84                     HECOX V. LITTLE


Court’s decision in Doe, 

, I agree with the
majority that this argument is unpersuasive.
    I take no issue with the general proposition that
“injunctive relief generally should be limited to apply only
to named plaintiffs where there is no class certification.”
Easyriders Freedom F.I.G.H.T. v. Hannigan, 

 (9th Cir. 1996); see United States v. Texas, 

, 1980 (2023) (Gorsuch, J., concurring) (“Traditionally,
when a federal court finds a remedy merited, it provides
party-specific relief, directing the defendant to take or not
take some action relative to the plaintiff. If the court’s
remedial order affects nonparties, it does so only
incidentally.”).
     Lindsay’s claims, however, are neither strictly facial nor
strictly as applied, and I join the majority in reading the
Supreme Court’s decision in Doe as approving of precisely
the kind of relief Lindsay seeks here. In Doe, the plaintiffs
were referendum petition signers who did not want their
names and addresses, or the names and addresses of other
referendum petition signers, disclosed under the state’s
Public Records Act (PRA). The Court explained that the
plaintiffs’ claim was neither purely facial nor purely as
applied:

       [The claim] obviously has characteristics of
       both: The claim is “as applied” in the sense
       that it does not seek to strike the PRA in all
       its applications, but only to the extent it
       covers referendum petitions. The claim is
       “facial” in that it is not limited to plaintiffs’
       particular case, but challenges application of
                        HECOX V. LITTLE                      85


       the law more broadly to all referendum
       petitions.
Doe, 

. Although the scope of permissible
remedies was not the issue before the Court, the Court made
clear that the plaintiffs could seek an injunction barring
enforcement of the PRA against non-plaintiffs:

       The label is not what matters. The important
       point is that plaintiffs’ claim and the relief
       that would follow—an injunction barring the
       secretary of state “from making referendum
       petitions available to the public”—reach
       beyond the particular circumstances of these
       plaintiffs. They must therefore satisfy our
       standards for a facial challenge to the extent
       of that reach.

 (citation omitted). Given Doe, and in light of the partially
facial nature of Lindsay’s claims, I agree with the majority
that the district court permissibly barred enforcement of the
Act beyond the individual Plaintiffs.
    The relief granted by the district court is consistent with
the principle that “an injunction ‘should be no more
burdensome to the defendant than necessary to provide
complete relief to the plaintiffs before the court.’” City &
County of San Francisco v. Barr, 

 (9th Cir.
2020) (quoting L.A. Haven Hospice, Inc. v. Sebelius, 

 (9th Cir. 2011)); see also E. Bay Sanctuary
Covenant v. Biden, 

 (9th Cir. 2021) (en
banc); Doe #1 v. Trump, 

 (9th Cir. 2020).
Enjoining enforcement of the Act against Lindsay, while
leaving it in place as to others, risks further stigmatizing her
because she would be isolated as the only transgender female
86                     HECOX V. LITTLE


athlete playing on women’s and girls’ teams in all of Idaho.
It would also deprive her of the opportunity to have
transgender teammates and the chance to compete against all
female athletes, including other transgender athletes. It
would therefore undermine two benefits Lindsay would
derive from participating in women’s sports: building
“camaraderie” and “forming relationships with [her]
teammates,” Lindsay Hecox decl. ¶ 8; Lindsay Hecox suppl.
decl. ¶ 22; and “competing” against other women and girls,
Lindsay Hecox decl. ¶¶ 22, 30, 32, 39; Lindsay Hecox suppl.
decl. ¶ 17.
                      IX. Conclusion
   For the foregoing reasons, I would affirm the district
court’s injunction in part, vacate it in part, and remand.
    The issues presented in this case are novel and difficult
and decisionmakers around the world are still in the process
of designing and implementing sensible standards regulating
the participation of transgender women and girls in women’s
sports. See generally Nondiscrimination on the Basis of Sex
in Education Programs or Activities Receiving Federal
Financial Assistance: Sex-Related Eligibility Criteria for
Male and Female Athletic Teams, 

,860–
22,891 (proposed Apr. 13, 2023) (to be codified at 

). Indeed, the parties’ briefs acknowledge that since
the district court ruled, some of the world’s leading athletic
organizations, including the International Olympic
Committee (IOC) and the NCAA, have revisited their
standards governing participation by transgender women in
                           HECOX V. LITTLE                            87


women’s athletics. Notably, both organizations continue to
allow transgender women to compete. 7
    The standards adopted by the IOC, the NCAA, and
others aim to balance a range of important values and

7
  In January 2022, the NCAA adopted “a sport-by-sport approach to
transgender participation that preserves opportunity for transgender
student-athletes while balancing fairness, inclusion and safety for all
who compete.” Press Release, NCAA, Board of Governors Updates
Transgender        Participation     Policy      (Jan.    19,     2022),
https://www.ncaa.org/news/2022/1/19/media-center-board-of-
governors-updates-transgender-participation-policy.aspx
[https://perma.cc/7ZFT-GA6L] (last visited July 27, 2023). Under the
NCAA standards, transgender student-athletes are allowed to compete
but may be required to “document sport-specific testosterone levels.”
Id.; see also Press Release, NCAA, Transgender Student-Athlete
Participation                                                     Policy,
https://www.ncaa.org/sports/2022/1/27/transgender-participation-
policy.aspx [https://perma.cc/FH8V-VVKA] (last updated Apr. 17,
2023). The IOC likewise follows a sport-by-sport approach. See Int’l
Olympic Comm., IOC Framework on Fairness, Inclusion and Non-
Discrimination on the Basis of Gender Identity and Sex Variations 1
(Nov.                              22,                            2021),
https://stillmed.olympics.com/media/Documents/Beyond-the-
Games/Human-Rights/IOC-Framework-Fairness-Inclusion-Non-
discrimination-2021.pdf [https://perma.cc/MX6D-Y4RG] (last visited
July 27, 2023). The IOC framework states that “[n]o athlete should be
precluded from competing or excluded from competition on the
exclusive ground of an unverified, alleged or perceived unfair
competitive advantage due to their sex variations, physical appearance
and/or transgender status,” and that, “[u]ntil evidence . . . determines
otherwise, athletes should not be deemed to have an unfair or
disproportionate competitive advantage due to their sex variations,
physical appearance and/or transgender status.” 

. It also states
that “criteria to determine eligibility for a gender category should not
include gynaecological examinations or similar forms of invasive
physical examinations, aimed at determining an athlete’s sex, sex
variations or gender.” 

.
88                     HECOX V. LITTLE


interests, including, among others, inclusion, non-
discrimination, competitive fairness, safety, and completing
the still unfinished and important job of ensuring equal
athletic opportunities for women and girls. See Women’s
Sports Found., 50 Years of Title IX: We’re Not Done Yet 3
(2022) (“Sports participation is vital to the development of
girls and women. The benefits are far-reaching and lifelong,
including improved physical, social, and emotional health;
enhanced confidence; academic success; leadership
opportunities; and so much more. Progress over the last 50
years is impressive, and yet it is not enough. The playing
field is not yet level—it’s not even close.”),
https://www.womenssportsfoundation.org/articles_and_rep
ort/50-years-of-title-ix-were-not-done-yet/ (last visited July
27, 2023). Policymakers have long recognized that women
must have an equal opportunity not only to participate in
sports but also to compete and win.
    In my understanding, nothing in today’s decision, or in
the district court’s decision, precludes policymakers from
adopting appropriate regulations in this field—regulations
that are substantially related to important governmental
interests. See Clark, 

. This court holds only
that the district court did not abuse its discretion in
concluding as a preliminary matter that Lindsay is likely to
succeed on her claim that this particular statute is not
substantially related to important governmental interests.