“What is a woman?”: the US Supreme Court must decide
On 13th January 2026, the United States Supreme Court will hear two cases which push it to adjudicate on what “sex” means in US equality law. Two states, Idaho and West Virginia, are defending their state laws to restrict female athletics to those born female.
These cases are, in effect, a US version of the For Women Scotland case, which established in UK equality law that sex always has its normal biological meaning. Sex Matters provided “Amicus Curiae” briefs to support the two states in the US cases in the public interest. (“Amicus Curiae”, meaning “friend of the court”, is similar to being an intervenor in the UK.) Our acting chair, Dr Emma HIlton, is part of a separate intervention by a group of academics.
» Read brief of Sex Matters on our website »
» Read brief of Emma Hilton PhD et al on our website »
The USA has no single law like Britain’s Equality Act. But it does have “Title IX”, which is part of its 1972 Education Amendments. This prohibits discrimination based on sex in education programmes and activities that receive federal financial assistance. It covers admissions, athletics, employment and student conduct, and has been influential in moving towards equal provision of facilities, funding and scholarships for girls and boys in high-school and college sports.
Title IX states:
“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.”
The legal issue for the court is what “on the basis of sex” means. If it means biology, as in the UK, then allowing trans-identifying boys or men into programmes or scholarships for women or girls violates Title IX since in effect it subjects women and girls to discrimination if there is no female category and they lose out on medals, scholarships and team places to boys. If, instead, a boy can count as a “transgender girl”, then schools and colleges can treat them as female without facing a discrimination challenge under Title IX.
Battles between state and federal law
Over the past few years, many US states have passed laws prohibiting school and college sport from allowing trans-identifying boys or men into female categories. Others have insisted that these “transgender girls” are girls. The divide is predictably partisan: Republican state legislatures have protected the female category; most Democrat-led states have not, and in a few cases a Democrat governor has blocked state legislation.
There have been legal challenges in both directions. Female students have brought cases against states such as Connecticut that allowed boys to claim high-school girls’ state championships; and against sports bodies, such as the National Collegiate Athletics Association (NCAA), which allowed Lia Thomas to swim in women’s national competitions. The Connecticut case is currently at the Court of Appeal, the last stage before the Supreme Court. A challenge in Minnesota, where a trans-identifying boy was part of a girls’ high-school team that won a state softball championship, has also reached Appeal level.
Meanwhile, trans-identifying students and the American Civil Liberties Union (ACLU) have challenged state laws that protect the female category and do not grant them access to the sports matching their claimed identity. Two of these cases have now reached the Supreme Court.
The cases in the Supreme Court this week
Two states, Idaho and West Virginia, are defending their state laws to restrict female athletics to those born female. The cases are The Governor of Idaho et al v Lindsay Hecox et al and West Virginia et al v BPJ.
The cases are being heard together because they are on the same point of law. Idaho was the first state to take action explicitly to protect female sport, with its Fairness in Women’s Sport law, passed in March 2020. A trans-identifying male, Lindsay Hecox, won an injunction against that law, the state appealed, and now the case has reached the highest level, the Supreme Court.
West Virginia followed Idaho with its own law a year later. That was challenged by BPJ, a trans-identifying young man whose puberty was blocked and who wanted access to girls’ high-school sport. Although the case was brought by the trans-identifying boy, the evidence now includes accusations that BPJ sexually harassed girls in his high school including in the girls’ changing room.
Both trans claimants have been assisted by the ACLU, which claims that these laws violate the equal-protection clause of the US Constitution. It says transgender people must be treated as the sex in which they identify, and the state laws need to be struck down.
What’s at stake?
There are now 27 states with similar laws protecting sport for women and girls. If these two cases are lost, then no state will be permitted to adopt such a law. All would have to adopt policies like those of California and Connecticut, which actively support “transgender girls” in female sport.
If the Supreme Court rules for the states in these defensive cases, it would mean that sex-based laws are permitted but not obligatory. California and other states would not be forced to adopt them.
If the cases being brought by female claimants against states such as Connecticut which require “trans inclusion” also reach the Supreme Court, they could determine that states must protect the female category on the basis of sex.
It is not just about sport. A declaration that sex in Title IX means biology would clarify the meaning of sex-discrimination protections across all federally funded education programmes. Like the For Women Scotland judgment in the UK Supreme Court, it would provide a strong indication that sex can only mean sex, anywhere it appears in law.
Signs that US media coverage is shifting towards reality
The Washington Post, a liberal paper that has long been sympathetic to “trans girls”, says in this editorial, published the day before the hearing, that neither science nor the American public is on the side of the trans athletes. It says:
“The Supreme Court has the chance this week to save women’s sports, allowing states to restore a level playing field for girls by excluding biological men and thereby correcting one of the worst excesses of America’s cultural revolution.”
Such a strong and unequivocal statement from a traditionally Democrat-leaning journal shows recognition that popular opinion on this issue is not with the trans-affirming Democrats.
Other articles, such as this backgrounder from sports outlet ESPN, continue to centre the demands of “transgender girls” as if they are rights.
Which way will it go?
The conservative majority in the US Supreme Court makes it likely that reality will prevail. In a sign that the trans claimants may feel this too, Lindsay Hecox asked the court not to hear the Idaho case, on the basis that he is no longer participating in sports in Idaho. The state governor requested that it be heard nonetheless, since he wants to establish that the Fairness in Women’s Sport statute is lawful.
Oral arguments will be heard this week. Judgment will be handed down in the coming months, with no further indication of likely timing.