Amicus Curiae Brief — Bradley Little, Governor of Idaho, et al., Petitioners v. Lindsay Hecox, et al.

Nos. 24-38, 24-43

444444444444444444444444444444444444444444

IN THE

Supreme Court of the United States

____________________

BRADLEY LITTLE, GOVERNOR OF IDAHO, ET AL.,

Petitioners,

v.

LINDSAY HECOX, ET AL., Respondents.

____________________

STATE OF WEST VIRGINIA, ET AL., Petitioners,

v.

B.P.J., BY NEXT FRIEND AND MOTHER, HEATHER

JACKSON, Respondent.

____________________

On Writs of Certiorari to the United States Courts of

Appeals for the Fourth and Ninth Circuits

____________________

Brief Amici Curiae of America’s Future, Public

Advocate of the US, Public Advocate Fdn.,

Clare Boothe Luce Center for Cons. Women,

U.S. Constitutional Rights Legal Def. Fund,

One Nation Under God Fdn., and

Cons. Legal Def. and Education Fund

in Support of Petitioners

____________________

JAMES N. CLYMER

Lancaster, PA

J. MARK BREWER

Johnson City, TX

WILLIAM J. OLSON*

JEREMIAH L. MORGAN

WILLIAM J. OLSON, P.C.

JOSEPH W. MILLER

Fairbanks, AK

370 Maple Ave. W., Ste. 4

Vienna, VA 22180

(703) 356-5070

wjo@mindspring.com

*Counsel of Record

Attorneys for Amici Curiae

September 19, 2025

RICK BOYER

Lynchburg, VA

444444444444444444444444444444444444444444

TABLE OF CONTENTS

Page

TABLE OF AUTHORITIES . . . . . . . . . . . . . . . . . . . . . . . iii

INTEREST OF THE AMICI CURIAE . . . . . . . . . . . . . . . . 1

STATEMENT OF THE CASE . . . . . . . . . . . . . . . . . . . . . 2

SUMMARY OF ARGUMENT. . . . . . . . . . . . . . . . . . . . . . 5

ARGUMENT

I.

THE FOURTH CIRCUIT ERRED IN RULING THAT

THE WEST VIRGINIA LAW PROTECTING

WOMEN IN SPORTS VIOLATED TITLE IX . . . . . . . 6

A.

Title IX Was Designed to Level the

Playing Field in School Athletics

between Biological Males and Biological

Females . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

B.

Title IX Allowed Biological Sex

Segregation to Protect Women in School

Sports from Male Intrusion. . . . . . . . . . . . 9

C.

The Text of Title IX Makes Clear It Was

Designed to Level the Playing Field in

School Athletics between Biological

Males and Females . . . . . . . . . . . . . . . . . 10

D.

The Regulatory History of Title IX

Makes Clear Its Intent to Level the

Playing Field in School Athletics

between Biological Males and Females . 12

ii

II. THE NINTH CIRCUIT ERRED IN RULING THAT

THE IDAHO LAW PROTECTING WOMEN IN

SPORTS VIOLATED THE EQUAL PROTECTION

CLAUSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

A.

The Reality of Sex Differences . . . . . . . . 17

B.

The Biology of Sex Differences . . . . . . . . 18

C.

The Immutability of Sex Differences . . . 21

D.

Recognition of Sex Differences Is Not

Invidious. . . . . . . . . . . . . . . . . . . . . . . . . . 22

E.

Failure to Recognize Sex Differences Is

Irrational . . . . . . . . . . . . . . . . . . . . . . . . . 25

CONCLUSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

iii

TABLE OF AUTHORITIES

Page

CONSTITUTION

Amendment XIV. . . . . . . . . . . . . . . 3, 4, 6, 18, 22, 25

STATUTES

20 U.S.C. § 1681 . . . . . . . . . . . . . . . . . . . . . . . . . . . .

20 U.S.C. § 1686 . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Idaho Code § 33-6201-06 . . . . . . . . . . . . . . . . . . . . .

WV Code § 18-2-25d . . . . . . . . . . . . . . . . . . . . . . . . .

2

6

4

2

CASES

Adams v. Sch. Bd. of St. Johns Cnty., 57 F.4th

791 (11th Cir. 2022) . . . . . . . . . . . . . . . . . . . . . 12

Bostock v. Clayton County, 590 U.S. 644

(2020) . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8, 15-17

Dep’t of Educ. v. Louisiana, 603 U.S. 866 (2024) . 16

Frontiero v. Richardson, 411 U.S. 677 (1973) . . . . 14

Labrador v. Poe, 144 S. Ct. 921 (2024) . . . . . . . . . . 4

Louisiana v. United States Dep’t of Educ., 2024

U.S. App. LEXIS 17886 (5th Cir. 2024) . . 16, 17

Michael M. v. Superior Court, 450 U.S. 464

(1981) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Parham v. Hughes, 441 U.S. 347 (1979) . . . . . . . . 18

Tennessee v. Cardona, 737 F. Supp. 3d 510

(E.D. Ky. 2024). . . . . . . . . . . . . . . . . . . . . . 11, 14

Tennessee v. Cardona, 2024 U.S. App. LEXIS

17600 (6th Cir. 2024) . . . . . . . . . . . . . . . . . 11, 16

United States v. Skrmetti, 145 S. Ct. 1816

(2025) . . . . . . . . . . . . . . . . . . . . . . 5, 17-19, 22-25

United States v. Virginia, 518 U.S. 515 (1996) . . . 15

REGULATIONS

40 Fed. Reg. 24134 (1975) . . . . . . . . . . . . . . . . . . . 13

iv

MISCELLANEOUS

118 Cong. Rec. 5803-5808 . . . . . . . . . . . . . . . . . . 8, 9

American College Dictionary (1970) . . . . . . . . . . . 15

American Heritage Dictionary of the English

Language (1st ed. 1969) . . . . . . . . . . . . . . . . . 15

M. Artigues & M. Cretella, “Sex is a Biological

Trait of Medical Significance,” American

College of Pediatricians (Mar. 2021) . . . . . 19, 20

A. Barnes, “American sprinter becomes most

decorated woman in Olympic track history,”

The Hill (Aug. 6, 2021) . . . . . . . . . . . . . . . . . . 22

A. Henkel, “Open letter to the International

Olympic Committee by Ana Paula Henkel,”

FairPlayforWomen.com (Dec. 13, 2018) . . . . . 25

C. Holcomb, “Biden preaches science while

ignoring it on high school sports,” N.Y.

Daily News (Feb. 5, 2021) . . . . . . . . . . . . . . . . 22

M. Joyner, S. Hunter & J. Senefeld, “Evidence

on sex differences in sports performance,”

J. APPL. PHYSIOL. 138, 274, 275, American

Physiological Society (Dec. 24, 2024) . . . . . . . 21

Random House College Dictionary (1973) . . . . . . 15

B. Sandler, “Title IX: How We Got It and What

a Difference It Made,” 55 CLEV. ST. L. REV.

473 (2007). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

E. Spitznagel, “Trans women athletes have

unfair advantage over those born female:

testosterone,” New York Post (July 10,

2021) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20, 21

U.S. Brief, Frontiero v. Laird, No. 71-1694,

1972 WL 137566 (U.S. Dec. 27, 1972). . . . . . . 14

v

S. Warren, “Doctors Verify the ‘Scientific

Evidence’ Proves Trans Swimmer Lia

Thomas’ Unfair Advantage Over Females,”

CBN News (May 31, 2022). . . . . . . . . . . . . . . . 20

Webster’s Third New International Dictionary

(1966) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14, 15

INTEREST OF THE AMICI CURIAE1

America’s Future, Public Advocate of the United

States, Public Advocate Foundation, Clare Boothe

Luce Center for Conservative Women, U.S.

Constitutional Rights Legal Defense Fund, One Nation

Under God Foundation, and Conservative Legal

Defense and Education Fund are nonprofit

organizations, exempt from federal income tax under

either section 501(c)(3) or 501(c)(4) of the Internal

Revenue Code. These entities, inter alia, participate

in the public policy process, including conducting

research, and informing and educating the public on

the proper construction of state and federal

constitutions, as well as statutes related to the rights

of citizens, and questions related to human and civil

rights secured by law.

Some of these amici filed amicus briefs at the

Petition stage in Little v. Hecox, Brief Amicus Curiae

of America’s Future, et al., No. 24-38 (Aug. 14, 2024),

and West Virginia v. B.P.J., Brief Amicus Curiae of

America’s Future, et al., No. 24-43 (Aug. 15, 2024), as

well as in the Fourth Circuit in B.P.J. v. West Virginia

State Board of Education, et al., Brief Amicus Curiae

of Public Advocate of the United States, et al., No. 231078 (May 3, 2023).

1

It is hereby certified that no counsel for a party authored this

brief in whole or in part; and that no person other than these

amici curiae, their members, or their counsel made a monetary

contribution to its preparation or submission.

2

STATEMENT OF THE CASE

Before this Court are two highly similar cases from

the Fourth and Ninth Circuits involving challenges to

state laws requiring that school sports teams be

separated by biological sex. As it is anticipated these

cases will be argued and decided together, these amici

are filing the same amicus brief in both cases.

West Virginia v. B.P.J.

In 2021, the West Virginia legislature enacted the

“Save Women’s Sports Bill,” WV Code § 18-2-25d (“the

Act”), to protect women’s sports by defining the terms

“female,” “girl,” and “woman” as describing biological

females. B.P.J., a biological male, who describes

himself as a “transgender girl,” seeking to compete on

the girls’ track and cross country teams, challenged the

law under both the Equal Protection Clause and Title

IX.

The district court initially granted a temporary

injunction against the law in July 2021. B.P.J. v. W.

Va. State Bd. of Educ., 550 F. Supp. 3d 347 (S.D. W.

Va. 2021). However, after discovery and considering

substantial evidence offered by the parties, the district

court reversed its position, dissolved its injunction, and

granted summary judgment to the State of West

Virginia in January 2023. B.P.J. v. W. Va. State Bd.

of Educ., 649 F. Supp. 3d 220 (S.D. W. Va. 2023) The

district court ruled that “the legislature’s chosen

definition of ‘girl’ and ‘woman’ in [the sports] context is

constitutionally permissible.” Id. at 233, 233.

3

Thereafter, the Fourth Circuit issued its own

injunction against the Act without opinion. B.P.J. v.

W. Va. State Bd. of Educ., 2023 U.S. App. LEXIS 8379

(4th Cir. 2023). This Court denied an application to

vacate that injunction. West Virginia v. B.P.J., 143 S.

Ct. 889 (2023). Joined in dissent by Justice Thomas,

Justice Alito wrote, “enforcement of the law at issue

should not be forbidden by the federal courts without

any explanation.... [I]n the circumstances present here

— where a divided panel of a lower court has enjoined

a duly enacted state law on an important subject

without a word of explanation, notwithstanding that

the District Court granted summary judgment to the

State based on a fact-intensive record — the State is

entitled to relief.” Id. at 889 (Alito, J., dissenting).

While the injunction was in place, Respondent B.P.J.

competed in girls’ track and field events, defeating a

significant number of biological girls in 2023 and 2024,

and taking spots from biological girls to compete in

conference championships.

Ultimately, the Fourth Circuit overturned the

district court’s decision, asserting that the district

court wrongly decided that West Virginia’s Act does

not violate the Equal Protection Clause and Title IX.

The court ruled that summary judgment should not

have been granted against B.P.J. without further

factual development of the question whether biological

males enjoy a competitive advantage over biological

females in sports competitions. B.P.J. v. W. Va. State

Bd. of Educ., 98 F.4th 542, 561 (4th Cir. 2024) (“BPJ

II”). It also directed the district court to enter

summary judgment against West Virginia on the Title

IX claims. Id. at 565.

4

Little v. Hecox

In March 2020, Idaho enacted the “Fairness in

Women’s Sports Act,” Idaho Code § 33-6201-06 (2020).

The law provided that only biological females may

compete on interscholastic women’s and girls’ teams in

Idaho state schools, allowing biological males to

compete in men’s and boys’ teams as well as

designated mixed-sex sports. Hecox v. Little, 479 F.

Supp. 3d 930, 943-44, 948 (D. Id. 2020) (“Hecox I”).

The Idaho law was challenged by a biological male

wishing to try out for the women’s cross country and

track teams at Boise State University.

The Idaho district court enjoined the Act, declaring

that it violated the Fourteenth Amendment’s equal

protection guarantee. Id. at 988-89. The injunction

barred enforcement of any portion of the Act against

any person. In August 2023, the injunction was

upheld by the Ninth Circuit. Hecox v. Little, 79 F.4th

1009 (9th Cir. 2023). Following this Court’s ruling in

Labrador v. Poe, 144 S. Ct. 921 (2024), relating to the

Idaho Vulnerable Child Protection Act, the Ninth

Circuit issued an amended opinion (Hecox v. Little, 104

F.4th 1061 (9th Cir. 2024) (“Hecox II”)). That amended

opinion remanded the case and stating that “the scope

of the injunction is not clear.... On remand, the

district court should tailor the injunction to provide ...

specificity.” Hecox II at 1089. The Ninth Circuit then

denied petitions for rehearing en banc as moot. Hecox

v. Little, 2024 U.S. App. LEXIS 14077 (9th Cir. 2024).

5

SUMMARY OF ARGUMENT

Our nation has been gripped by what could be

termed transgender mania for more than a decade.

Although every effort has been made by psychiatrists

to alter their technical diagnoses to please the

transgender advocates (e.g., “gender dysphoria”

replacing “Gender Identity Disorder” replacing “gender

identity disturbance”), transgenderism remains a

disorder of dissatisfaction with the reality of one’s sex.

For many years, plaintiffs asserting transgender

status have demanded the government bend to their

ever-increasing demands, even at the expense of all

others. All too often, these plaintiffs have been treated

by courts as if they were members of a protected class.

The medical community has demanded the right to

disfigure the bodies of such minors, and in response,

several states have acted to protect minors from

elements of the medical establishment eager to profit

from such horrific acts. Fortunately, this Court acted

to protect minors in Skrmetti.

Now, in response to a different, yet serious, threat

to women, states such as West Virginia and Idaho

have acted to prevent certain boys and men from

invading girls’ and women’s sports. In the two cases

now before the Court, certain male students, some

with a mental or spiritual disorder, and some possibly

because they have not had success competing against

other men, have declared themselves transgender to

gain eligibility to use their natural, physical

advantages in a profoundly unfair manner. The courts

below have yielded to this demand.

6

The phrase “on the basis of sex” in Title IX cannot

be read to mean anything but males and females. To

yield to the demand of the transgender plaintiffs

requires that the purpose of Title IX be not only

ignored, but upended. The Equal Protection Clause

was not designed to protect transgenderism, which in

no way can be considered a protected class.

Fortunately, this case is coming before this Court

toward the end of the period of transgender mania,

allowing clear thinking to prevail. The decisions below

should be reversed.

ARGUMENT

I.

THE FOURTH CIRCUIT ERRED IN RULING

THAT THE WEST VIRGINIA LAW

PROTECTING WOMEN IN SPORTS

VIOLATED TITLE IX.

The Fourth Circuit directed the district court to

enter summary judgment against West Virginia on the

Title IX claims. BPJ II at 565. No doubt, Respondents

will argue in this Court, as below, that five words

contained in Title IX dictate the result of this case:

“No person in the United States shall, on the basis of

sex, be excluded from participation in, be denied the

benefits of, or be subjected to discrimination under any

education program or activity receiving Federal

financial assistance.” 20 U.S.C. § 1681(a) (emphasis

added). And, no doubt, again, the strongest argument

that Respondents will have available is this Court’s

decision in Bostock v. Clayton County, 590 U.S. 644

(2020), addressing the words “because of ... sex” where

they are used in Title VII of the Civil Rights Act of

7

1964. These amici continue to believe that Bostock

was wrongly decided,2 but fortunately, there is no need

to revisit Bostock to decide this case. First, this Court

expressly disclaimed any intention to apply Bostock

beyond Title VII:

The employers worry that our decision will

sweep beyond Title VII to other federal or

state laws that prohibit sex discrimination.

And, under Title VII itself, they say

sex-segregated bathrooms, locker rooms, and

dress codes will prove unsustainable after our

decision today. But none of these other laws

are before us; we have not had the benefit

of adversarial testing about the meaning

of their terms, and we do not prejudge

any such question today. Under Title VII,

too, we do not purport to address bathrooms,

locker rooms, or anything else of the kind.

[Bostock at 681 (emphasis added).]

Moreover, as Petitioners argue (W.V. Pet. Br. at

17, 29-31), this Court’s holding in Bostock does not

control here, and indeed is inapplicable to Title IX.

And even if the Court found once sufficient ambiguity

to shoehorn a policy choice never entertained or

desired by Congress into the phrase “because of ... sex”

in Title VII, similar language employed in Title IX

cannot be so read. “Sex” in Title IX expressly refers to

2

See Brief Amicus Curiae of Public Advocate of the United

States, et al., Bostock v. Clayton County, Georgia & Altitude

Express v. Zarda, U.S. Supreme Court Nos. 17-1618 and 17-1623

(Aug. 23, 2019).

8

two biological sexes, male and female. Indeed, the

express purpose of Title IX was to protect females from

imbalances in education — including in the context of

sports — that favored biological males over biological

females. To jam the square peg of Bostock into the

round hole of Title IX would effectively overturn Title

IX, hopelessly vitiating the purpose for which the law

was enacted.

A. Title IX Was Designed to Level the Playing

Field in School Athletics between

Biological Males and Biological Females.

Any argument that Bostock could have any

application to Title IX requires a complete disregard

for the reason Title IX was enacted. Title IX Senate

sponsor Birch Bayh (D-IN) introduced the legislation,

stating that its object was to ensure that females have

the same educational opportunities available to males.

Senator Bayh attacked “corrosive and unjustified

discrimination against women.” 118 Cong. Rec. 5803.

He stressed that the bill was designed to address

preferential treatment for biological males over

females. He denounced stereotypes of females as

“pretty things who go to college to find a husband …

and finally marry, have children and never work

again.” 118 Cong. Rec. 5804.

Senator Bayh repeatedly lamented disparate

opportunities in education and employment between

“men” and “women.” “I am concerned that in 1970 the

percentage of the female population enrolled in college

was markedly lower than the percentage of the male

population….” 118 Cong. Rec. 5805. He further

9

added, “[i]t is of little comfort for women to know that

they are encouraged to further their schooling but that

… they will be earning far less than male colleagues

for the rest of their lives.” 118 Cong. Rec. 5807.

However, Senator Bayh noted that Title IX’s language

dealt expressly with differentiations on the basis of

“sex.” “Central to my amendment are sections

1001-1005 which would prohibit discrimination on the

basis of sex in federally funded education programs.”

118 Cong. Rec. 5807. Section 1007 of Title IX required

the Commissioner of Education to “investigate sex

discrimination at all levels of education ... and report

... recommendations for action to guarantee equality of

opportunity in education between the sexes.” 118

Cong Rec. 5808.

B. Title IX Allowed Biological Sex

Segregation to Protect Women in School

Sports from Male Intrusion.

In his remarks, Senator Bayh made clear that

Title IX would prohibit one of the results of allowing

men identifying as women to compete — “differential

treatment by sex” “in sports facilities or other

instances where personal privacy must be

preserved.” 118 Cong. Rec. 5807 (emphasis added).

Nothing in the language of Title IX even contemplates

allowing biological males to invade the locker rooms

and bathrooms used by biological female students

engaged in school sports.

Dr. Bernice Sandler, a pioneer instrumental in the

enactment of Title IX, recognized what advocates of

transgender ideology and too many courts fail to

10

recognize. That is, in sports, “some sex segregation is

necessary. If all teams were integrated by sex, few

women would have access to sports.” B. Sandler, “Title

IX: How We Got It and What a Difference It Made,” 55

CLEV. ST. L. REV. 473, 482 (2007). That is precisely the

evil Title IX sought to remedy.

Allowing men identifying as women to compete in

women’s sports threatens the success of Title IX. Until

Title IX’s passage, Sandler wrote, “discrimination

against women in collegiate athletics was pervasive

and substantial.” Id. at 480. Reflecting back on 35

years of Title IX in 2007, Sandler wrote that “college

women are now approximately forty percent of varsity

athletes. Despite these increases, we still have a very

long way to go to reach equity in athletics. Of all the

areas that Title IX covers, sports and athletics is the

area where most ... schools at all levels are still out of

compliance.”

Id. at 487.

Now “transgender”

participation threatens to ruin Title IX’s dream of

scholastic athletic equity forever.

C. The Text of Title IX Makes Clear It Was

Designed to Level the Playing Field in

School Athletics between Biological Males

and Females.

The text of Title IX embodies Senator Bayh’s plan

to promote women in sports, not men identifying as

women. There was no concept of “gender identity”

contemplated or incorporated in either the statute’s

intent or its text. As one court recently noted:

11

Title IX carves out exceptions for a number of

traditional male-only or female-only activities,

as long as similar opportunities provided for

“one sex” are provided for “the other sex.” See

20 U.S.C. §1681(a)(1)-(8).... Senator Bayh, one

of the proposal’s architects, stressed that Title

IX “provide[d] equal access for women and

men students to the educational process,” but

did not “desegregate” spaces and activities

that have long been sex-separated. 117 Cong.

Rec. 30407 (1971). [Tennessee v. Cardona, 737

F. Supp. 3d 510, 524 (E.D. Ky. 2024)

(“Cardona I”).]

There is a massive structural difference between

Title VII and Title IX, in that Title IX explicitly carves

out areas where specific federally funded programs are

textually entitled to make distinctions on the basis of

the biological realities of sex. Title VII does not. In an

on-point ruling upheld by this Court, the Sixth Circuit

recently noted:

As many jurists have explained, Title VII’s

definition of discrimination, together with the

employment-specific defenses that come with

it, do not neatly map onto other areas of

discrimination.... Title VII’s definition of sex

discrimination under Bostock simply does not

m ea n t he same t hi ng for ot her

anti-discrimination mandates, whether under

the Equal Protection Clause, Title VII, or Title

IX. [Tennessee v. Cardona, 2024 U.S. App.

LEXIS 17600 at *8 (6th Cir. 2024) (“Cardona

II”).]

12

While Title VII makes no textual “carveouts” for

when sex differences may be considered in the

employment context, Title IX expressly does so in the

educational context, and those carveouts are expressly

based on the inherent biological differences between

males and females.

One of these carveouts is that Title IX expressly

allows schools to maintain “separate living facilities”

by biological sex. “Notwithstanding anything to the

contrary contained in this title, nothing contained

herein shall be construed to prohibit any educational

institution receiving funds under this Act, from

maintaining separate living facilities for the different

sexes.” 20 U.S.C. § 1686. It is incomprehensible that

the text of Title IX permits sex-segregated college

cafeterias or laundry rooms, but not sex-segregated

sports teams, where the biological advantages of males

are manifest.

D. The Regulatory History of Title IX Makes

Clear Its Intent to Level the Playing Field

in School Athletics between Biological

Males and Females.

The Eleventh Circuit is in accord, noting that the

implementing regulations for Title IX expressly allow

for “‘separate toilet, locker room, and shower facilities

on the basis of sex,’ so long as the facilities ‘provided

for students of one sex [are] comparable to such

facilities provided for students of the other sex.’”

Adams v. Sch. Bd. of St. Johns Cnty., 57 F.4th 791,

811 (11th Cir. 2022) (quoting 34 C.F.R. § 106.33)

(emphasis added).

13

Notably, the DOE’s implementing regulations for

Title IX themselves envision the actual binary world of

two biological sexes. The way the DOE Office of Civil

Rights (“OCR”) interpreted Title IX at the time of its

passage is instructive. OCR promulgated regulations

in 1975 to initially implement Title IX.

The

implementing regulations clearly envisioned two —

and only two — distinct sexes, and were intended to

close the gap between biological males and females in

school athletics:

The Department’s intent ... is to require

institutions to take the interests of both sexes

into account in determining what sports to

offer. As long as there is no discrimination

against members of either sex, the institution

may offer whatever sports it desires.... In so

doing, an institution should consider by a

reasonable method it deems appropriate, the

interests of both sexes. [40 Fed. Reg. 24134

(1975) (emphasis added).

The regulations, in these earliest days of Title IX,

also “permit[ted] separate teams for members of

each sex where selection for the team is based on

competitive skill or the activity involved is a

contact sport.” Id. (emphasis added). Clearly, the

text recognizes and expressly accounts for inherent

biological differences between men and women.

It is a blatant departure from the intent and text

of Title IX to socially construct gender contrary to

simple biology. In the intervening half-century,

Congress has never redefined the word “sex” relative

14

to Title IX in a manner so patently contrary to the

legislation’s text or intent. Indeed, “‘Title IX was

enacted in response to evidence of pervasive

discrimination against women with respect to

educational opportunities....’ [U]ndercutting that

purpose ... creates myriad inconsistencies with Title

IX’s text and its longstanding regulations.” Cardona

I at 535-36. “This is an impermissible result.” Id. at

535.

When Congress enacted Title IX in 1972, the only

commonly understood meaning of “sex” was biological

sex. In that same year, 1972, the United States

explained to the Supreme Court that “sex, like race

and national origin, is a visible and immutable

biological characteristic.” U.S. Br. at *15, Frontiero v.

Laird, No. 71-1694, 1972 WL 137566 (U.S. Dec. 27,

1972). The Supreme Court determined that “sex” is

“an immutable characteristic determined solely by the

accident of birth.” Frontiero v. Richardson, 411 U.S.

677, 686 (1973).

All popular dictionaries at that time defined “sex”

as referring to the physiological distinctions between

males and females. The dictionaries defined only two

sexes and did so with reference to the reproductive

functions of the two.

Webster’s Third New

International Dictionary defined “sex” as “one of the

two divisions of organic esp. human beings

respectively designated male or female,” or “the sum of

the morphological, physiological, and behavioral

peculiarities of living beings that subserves biparental

15

reproduction.”3 Other contemporaneous dictionaries

defined “sex” similarly. The Random House College

Dictionary at 1206 (1973) defined sex as “1. either the

male or female division of a species esp. as

differentiated with reference to the reproductive

functions. 2. The sum of the structural and functional

differences by which male and females are

distinguished.” The American College Dictionary at

1109-10 (1970) defined “sex” as “1. The character of

being either male or female ... 2. The sum of the

anatomical and physiological differences with

reference to which the male and female are

distinguished or the phenomena depending on these

differences.” The American Heritage Dictionary of the

English Language at 1187 (1st ed. 1969) defined “sex”

as “1. a. The property or quality by which organisms

are classified according to their reproductive functions.

b. Either of two divisions, designated male and female,

of this classification.”

From 1972 until 2021, the Department of

Education always defined “sex” as referring to two

biologically exclusive sexes. There is no basis in the

text or history of Title IX to expand Bostock beyond

Title VII. As Justice Ginsburg famously wrote for this

Court, “Physical differences between men and women,

however, are enduring: ‘The two sexes are not

fungible; a community made up exclusively of one [sex]

is different from a community composed of both.’”

United States v. Virginia, 518 U.S. 515, 533 (1996)

(quoting Ballard v. United States, 329 U.S. 187, 193

3

Webster’s Third New International Dictionary at 2081 (1966).

16

(1946)). Indeed. And a sports team including males is

inherently different from one including only females —

and has a built-in biological competitive advantage.

Last year, this Court quite properly signaled that

it would respect the understanding of the drafters, and

not attempt to impose Bostock onto Title IX. The Sixth

Circuit, in Cardona II, and the Fifth Circuit, in

Louisiana v. United States Dep’t of Educ., 2024 U.S.

App. LEXIS 17886 (5th Cir. 2024), rejected an effort by

the Biden administration’s Department of Education

(“DOE”) to “defin[e] ‘discrimination on the basis of sex’

in Title IX to extend to discrimination on the basis of

‘gender identity,’ among other categories.” Cardona II

at *7-8. As the Sixth Circuit noted, “the Department

mainly relied on Bostock v. Clayton County” as

somehow offering support for the DOE’s redefinition of

“sex” in Title IX. Id. at *8. The Sixth Circuit rejected

the claim expressly, while the Fifth Circuit did so

implicitly, but both circuits opted to enjoin the

redefinition as atextual and without statutory

authority.

Notably, this Court upheld both injunctions,

finding that the plaintiffs were likely to prevail on the

merits: “Importantly, all Members of the Court today

accept that the plaintiffs were entitled to preliminary

injunctive relief as to three provisions of the rule,

including the central provision that newly defines sex

discrimination to include discrimination on the basis

of sexual orientation and gender identity.” Dep’t of

Educ. v. Louisiana, 603 U.S. 866, 867 (2024).

17

Given the legislative history of Title IX, this Court

in Louisiana reached the only coherent outcome. It

should do so again, finding that Bostock is simply

inapplicable outside the Title VII context, and

particularly in the Title IX context.

II.

THE NINTH CIRCUIT ERRED IN RULING

THAT THE IDAHO LAW PROTECTING

WOMEN IN SPORTS VIOLATED THE

EQUAL PROTECTION CLAUSE.

A. The Reality of Sex Differences.

This Court’s recent opinion in United States v.

Skrmetti, 145 S. Ct. 1816 (2025) provides some context

to the battle by some to crush biological distinctions

between the sexes. Skrmetti’s holding turned on this

Court’s determination that a Tennessee statute

banning chemical castration and genital and other

surgeries for minors differentiated on the basis of age,

not sex, and thus, rational basis scrutiny applied. But

Skrmetti stands for a broader principle than just the

type of balancing test which should be applied. In

Skrmetti, this Court quite properly signaled that

statutes that affect “transgender” individuals do not

automatically discriminate “on the basis of sex,” and

Justice Barrett’s concurrence cements this conclusion.

Skrmetti at 1855 (Barrett, J., concurring). This

Court’s equal protection analysis is clear that not all

sex-based classifications, including those involving

transgender persons, are inherently invidious.

There has been a trend of courts sanctioning

disparate treatment of biological men and women, that

18

should have application to those imagining themselves

to be of a different sex. In Parham v. Hughes, 441 U.S.

347 (1979), this Court upheld a Georgia statute which

permitted the mother of an illegitimate child to file

wrongful death actions if the child died, but forbade a

father to do so unless he first “legitimated” the child.

The Court reasoned that while the mother of an

illegitimate child would generally be known, proving

the identity of the father is sometimes more difficult,

and thus men and women are not similarly situated.

The Equal Protection Clause is not offended by

requiring the father to prove paternity before being

able to file a wrongful death action.

Two years later, in Michael M. v. Superior Court,

450 U.S. 464 (1981), this Court upheld a statute

criminally punishing males for sexual intercourse with

minors, while imposing no such punishment against

females. This Court stated, “[w]e need not be medical

doctors to discern that young men and young women

are not similarly situated with respect to the problems

and the risks of sexual intercourse. Only women may

become pregnant, and they suffer disproportionately

the profound physical, emotional, and psychological

consequences of sexual activity.”

Id. at 471.

Accordingly, as in Parham, the sex-based classification

was not invidious, and the legislature’s rational basis

of preventing teen pregnancy was sufficient to justify

the classification.

B. The Biology of Sex Differences.

In Skrmetti, this Court again recognized that some

differences between men and women are simply

19

biological and immutable, and laws that recognize and

accommodate for these differences are not inherently

invidious:

This Court has never suggested that mere

reference to sex is sufficient to trigger

heightened scrutiny.... Such an approach,

moreover, would be especially inappropriate in

the medical context. Some medical treatments

and procedures are uniquely bound up in sex.

The Food and Drug Administration itself

recognizes that “[r]esearch has shown that

biological differences between men and women

(differences due to sex chromosome or sex

hormones) may contribute to variations seen

in the safety and efficacy of drugs, biologics,

and medical devices.” [Skrmetti at 1829-30.]

Finding a mere reference to sex to be invidious

would be just as inappropriate in the sports context —

for the same medical reasons.

Whatever the

prevailing political opinion, the science is unyielding

— biological males on average possess physiological

advantages that tilt the playing field against biological

females. The addition of the label “transgender” does

nothing to subtract that advantage. It’s not politics;

it’s biology, especially testosterone.

The predominant influence affecting male

versus female athletic performance is

hormonal.... The sex hormone testosterone

plays an important role in regulating bone

mass, fat distribution, muscle mass and

strength, and the production of red blood cells

20

leading to higher circulating hemoglobin.

After puberty, male circulating testosterone

concentrations are 15 times greater than those

of females at any age. The result is a clear

male advantage in regard to muscle mass,

strength and circulating hemoglobin levels

even after adjusting for sex differences in

height and weight. On average, females have

50-60% of male’s upper arm muscle

cross-sectional area and 65-70% of male’s

thigh muscle cross-sectional area with a

comparable reduction in strength. Young

males have on average a skeletal muscle mass

over 12kg greater than age-matched females

at any given body weight.... Taken together,

these discrepancies render females, on

average, unable to compete effectively against

males in power-based or endurance-based

sports.4

Dr. Carole Hooven, the co-director of

undergraduate studies in human evolutionary biology

at Harvard, states the obvious: “There is a large

performance gap between healthy normal populations

of males and females, and that is driven by

testosterone.”5 Dr. Hooven notes, “In 2019, about

2,500 men, almost one-third of the total number of

4

M. Artigues & M. Cretella, “Sex is a Biological Trait of Medical

Significance,” American College of Pediatricians (Mar. 2021).

5

S. Warren, “Doctors Verify the ‘Scientific Evidence’ Proves

Trans Swimmer Lia Thomas’ Unfair Advantage Over Females,”

CBN News (May 31, 2022).

21

men competing worldwide in the [International

Amateur Athletic Federation] 100-meter event, beat

the fastest women’s time. Without segregation, it’s not

just that men would win — women would never even

qualify for the competitions in the first place.”6

C. The Immutability of Sex Differences.

All the medical efforts to erase this advantage in

the name of politics have proven unsuccessful. The

application of puberty blockers in males cannot erase

the biological imbalance between the sexes, as the

differences are apparent even before puberty.

“[A]mong the best prepubescent athletes in the United

States, the male-female performance gap is ~ 3%–5%

in track and field running events ... and ~ 5%–10% in

jumping events.”7 Suppressing testosterone in males

does not close the gap. “[T]estosterone suppression is

associated with modest reductions in both muscle mass

and muscle strength, but a large sex-based difference

in muscle mass and strength is retained.” Id. at 278.

Nor will testosterone supplementation in females close

the gap. “[T]estosterone supplementation in female

athletes is unlikely to erase the puberty-driven male

advantage in sports performance.” Id. at 279.

6

E. Spitznagel, “Trans women athletes have unfair advantage

over those born female: testosterone,” New York Post (July 10,

2021).

7

M. Joyner, S. Hunter & J. Senefeld, “Evidence on sex

differences in sports performance,” J. APPL. PHYSIOL. 138, 274,

275, American Physiological Society (Dec. 24, 2024).

22

Olympic sprinter Allyson Felix “is a six-time

Olympic gold medalist and holds numerous World

Championship titles. Yet in 2018, 275 high school

boys ran faster times than Felix’s lifetime best.”8 Felix

is “the most decorated woman in Olympic track and

field history.”9 But she would have been only 276th

best among U.S. male high school athletes in 2018.

Biology, that is, science, is undeterred by political

labels, and the legislative classifications created by

West Virginia and Idaho simply recognize the

scientific reality. They are not invidious.

D. Recognition of Sex Differences Is Not

Invidious.

In her Skrmetti concurrence, Justice Barrett noted

that this Court has never recognized “transgender”

status as a protected class for Equal Protection

purposes, and described how that status utterly fails

to meet this Court’s test. “Indeed, this Court ‘has not

recognized any new constitutionally protected classes

in over four decades, and instead has repeatedly

declined to do so.’” Skrmetti at 1850 (Barrett, J.,

concurring).

To determine whether a group constitutes a

“suspect class” akin to the canonical examples

of race and sex, we apply a test derived from

8

C. Holcomb, “Biden preaches science while ignoring it on high

school sports,” N.Y. Daily News (Feb. 5, 2021).

9

A. Barnes, “American sprinter becomes most decorated woman

in Olympic track history,” The Hill (Aug. 6, 2021).

23

the famous footnote 4 in United States v.

Carolene Products Co.... We consider whether

members of the group in question “exhibit

obvious, immutable or distinguishing

characteristics that define them as a discrete

group,” whether the group has, [a]s a historical

matter, ... been subjected to discrimination,

and whether the group is a minority or

politically powerless.... The test is strict, as

evidenced by the failure of even vulnerable

groups to satisfy it: We have held that the

mentally disabled, the elderly, and the poor

are not suspect classes.... In fact, as far as I

can tell, we have never embraced a new

suspect class under this test. [Id. at 1851

(Barrett, J., concurring) (internal quotations

omitted).]

“To begin,” Justice Barrett points out:

transgender status is not marked by the same

sort of obvious, immutable, or distinguishing

characteristics as race or sex.... In particular,

it is not defined by a trait that is definitively

ascertainable at the moment of birth. The

plaintiffs here, for instance, began to

experience gender dysphoria at varying ages....

Meanwhile, the plaintiffs acknowledge that

some transgender individuals “detransition”

later in life.... Accordingly, transgender status

does not turn on an immutable ...

characteristi[c]. [Id. (internal quotations

omitted).]

24

“Nor is the transgender population a ‘discrete

group,’ as our cases require. Instead, like classes we

have declined to recognize as suspect, the category of

transgender individuals is large, diverse, and

amorphous.... The ... term ‘transgender’ can describe

‘a huge variety of gender identities and expressions.’”

Id. at 1852 (internal quotations omitted).

Finally, Justice Barrett added, “holding that

transgender people constitute a suspect class would

require courts to oversee all manner of policy choices

normally committed to legislative discretion.” Id.

Among these permissible legislative choices, Justice

Barrett noted, is the historical ability of a state,

unchallenged from the adoption of the Fourteenth

Amendment until a few years ago, to keep male

athletes from competing on girls’ sports teams:

[T]ransgender status implicates several other

areas of legitimate regulatory policy —

ranging from access to restrooms to eligibility

for boys’ and girls’ sports teams. If laws that

classify based on transgender status

necessarily trigger heightened scrutiny, then

the courts will inevitably be in the business of

“closely scrutiniz[ing] legislative choices” in all

these domains.... [L]egislatures have many

valid reasons to make policy in these areas,

and so long as a statute is a rational

means of pursuing a legitimate end, the

Equal Protection Clause is satisfied. [Id.

at 1852-53 (Barrett, J., concurring) (emphasis

added).]

25

E. Failure to Recognize Sex Differences Is

Irrational.

The states in these cases have easily posited a

rational basis for their policy choices — indeed, the

very basis for which Title IX was created by its

framers, to end longstanding unequal treatment of

biological women and girls in education, including

educational sports programs. As Brazil’s Olympian

volleyball athlete Ana Paula Henkel wrote in an open

letter to the International Olympic Committee, the

“heedless decision to include biological men, born and

built with testosterone, with their height, their

strength and aerobic capacity of men, is beyond the

sphere of tolerance.

It represses, embarrasses,

humiliates and excludes women.”10 As Petitioner West

Virginia notes, “[b]ecause of these [biological and

physiological] differences, males would displace

females to a substantial extent if they were allowed to

compete together. With sex-specific sports, women

have a chance to compete fairly while not risking their

safety against physiologically distinct competitors.”

W.V. Pet. Br. at 4 (internal quotation omitted). This is

an eminently rational basis for the challenged laws.

And thus, as this Court suggests in Skrmetti and

Justice Barrett demonstrates, the Equal Protection

Clause is not offended.

10

A. Henkel, “Open letter to the International Olympic

Committee by Ana Paula Henkel,” FairPlayforWomen.com (Dec.

13, 2018).

26

CONCLUSION

For the foregoing reasons, the decisions of the

Fourth and Ninth Circuits should be reversed.

Respectfully submitted,

JAMES N. CLYMER

CLYMER MUSSER &

SARNO, P.C.

408 W. Chestnut St.

Lancaster, PA 17603

J. MARK BREWER

209 N. Nugent Ave.

WILLIAM J. OLSON*

JEREMIAH L. MORGAN

WILLIAM J. OLSON, P.C.

370 Maple Ave. W., Ste. 4

Vienna, VA 22180

(703) 356-5070

wjo@mindspring.com

*Counsel of Record

Johnson City, TX 78636

RICK BOYER

JOSEPH W. MILLER

Integrity Law Firm

P.O. Box 10953

Lynchburg, VA 24506

Law Offices of Joseph Miller, LLC

September 19, 2025

Attorneys for Amici Curiae

P.O. Box 83440

Fairbanks, AK 99708