Attorneys arguing against ban on trans-identified male athletes in girls' sports at Supreme Court refuse to define 'sex'

By Michael Gryboski, Editor Tuesday, January 13, 2026

Attorneys who were challenging state laws barring male athletes from competing in girls’ sports refused to fully define the term “sex” when arguing their cases before the United States Supreme Court.

The Supreme Court heard oral arguments on Tuesday in two related cases, Lindsay Hecox et al. v. Bradley Little, et al. and State of West Virginia v. B.P.J.

The Hecox case centered on a trans-identified athlete suing to strike down an Idaho law known as the Fairness in Women's Sports Act. The state law was blocked by a three-judge panel of the Ninth U.S. Circuit Court of Appeals in August 2023, upholding a lower court preliminary injunction against it.

The B.P.J. case involved a challenge by a trans-identified athlete to West Virginia's Save Women's Sports Act of 2021. In February 2023, a three-judge panel of the Fourth U.S. Circuit Court of Appeals issued a 2-1 decision reinstating an earlier lower court ruling that blocked the legislation.

Kathleen Hartnett represented Lindsay Hecox, a trans-identified student-athlete who is male but self-identifies as female and sought to compete in girls’ sports. 

At one point, Justice Samuel Alito asked Harnett if she agreed that a school could have “separate teams for a category of students classified as boys and a category of students classified as girls?”

“Yes, your honor,” she replied.

Alito then asked if the school did that, “Is it not necessary for there to be, for equal protection purposes, if that is challenged under the Equal Protection Clause, an understanding of what it means to be a boy or a girl, or a man or a woman?”

“Yes, your honor,” Hartnett answered.

When Alito immediately asked “what is that definition” for boy and girl “for equal protection purposes,” Hartnett responded that “I think that the underlying enactment, whatever it was, the policy, the law, we’d have to have an understanding of how the state or the government was understanding that term to figure out whether or not someone was excluded.”

“We do not have a definition for the court,” Hartnett said. “We’re not disputing the definition here. What we’re saying is that the way it applies in practice is to exclude birth-sex males categorically from women’s teams.”

“There’s a subset of those birth-sex males where it doesn’t make sense to do so, according to the state’s own interest.”

Alito responded by asking Hartnett, “How can you, how can a court determine whether there’s discrimination on the basis of sex without knowing what sex means, for equal protection purposes?”

Harnett replied that she was using the definitions of sex outlined in the challenged Idaho statute, which, according to her, makes Hecox a “birth-sex male” and that Hecox “was being excluded” from competing on a girls’ team because he is male. 

Alito then asked whether a male who has not undergone any trans procedures and who still insists that he is a female could be barred from a girls-only team, with Hartnett agreeing.

“I would respect their self-identity in addressing the person, but in terms of the statute, I think the question is, does that person have a sex-based biological advantage?” she replied.

Hartnett went on to note that she was not advocating for “absolute inclusion,” believing that Hecox had removed any unfair sex-based advantages via trans medicalization. 

Joshua Block represented the minor labeled “B.P.J.” in court documents, reportedly the only trans-identified student trying to play on a girls’ sports team in West Virginia.

During the arguments, Block urged the high court “not to do it based on a definition of sex argument,” adding that “we are not disputing, in this case, that West Virginia can have its definition of sex.”

“Our argument is it’s using this definition to inflict discrimination in denial [of] equal athletic opportunity, but we are not saying their definition of sex is wrong,” Block said.

“However, I don’t think it follows that Title IX created some national definition of sex that preempted states’ ability to say ‘you know, actually, we are most concerned about discrimination that happens through gender roles.’”

Justice Brett Kavanaugh interjected, asking if Block thinks that the word “sex” in federal Title IX antidiscrimination law “can reasonably be interpreted to allow different states to take different understandings of that in their sports leagues?”

“I do,” Block replied. “Because I don’t think the purpose of Title IX is to have an accurate definition of sex. I think the purpose is to make sure that sex isn’t being used to discriminate by denying opportunities.”

Along those lines, Block further argued that Title VI of the federal civil rights law did not require a specific definition of race to be used to stop discrimination on the basis of race.

“I wouldn’t look to whether or not it’s accurate to classify B.P.J. as male or female,” he continued. “I think the question is, is [he] being denied an opportunity because of that classification?”

Alito told Block that “Title IX prohibits discrimination on the basis of sex. It’s a statutory term. It must mean something.”

“You’re arguing that here, there’s discrimination on the basis of sex,” continued Alito. “How can we decide that question without knowing what ‘sex’ means in Title IX?”

“It could mean biological sex, it could mean gender identity, it could mean whatever a state wants to find it to mean. But it has to mean something. How can we decide that without knowing what the statutory term means?”

Block argued that there is “a whole range of sex-based characteristics that can give rise to discrimination,” including ideas like “biological differences” and “gender presentation,” but hesitated to elevate “gender identity” as “the new definition of sex.”

Chief Justice John Roberts asked whether Block believes the Supreme Court shouldn't have “an operating definition of sex in Title IX?”

“When it is used as a statutory term, I’m not sure you have that kind of flexibility,” Roberts added. “The question then would be instead ‘what does Congress think the word means?’”

“We’re not trying to police the accuracy of the terminology,” Block argued. “All I am saying is that what’s being prohibited is using this classification to discriminate.”

In recent years, several states have enacted laws prohibiting male students who identify as female from competing on girls-only athletic teams, citing concerns about fairness.

The Christian Post reported last year that trans-identified male athletes have stolen over 1,900 gold medals from women and girls, according to data compiled by the advocacy group Concerned Women for America. 

State laws protecting girls' and women's sports have sometimes been met with litigation from progressive groups that claim these measures unlawfully discriminate against trans-identified student athletes who want to compete against the opposite sex instead of their own sex. 

In advance of oral arguments, the left-leaning editorial board of The Washington Post expressed their support for the state laws, saying that “the laws being challenged are reasonable concessions to immutable reality.”

“Is there evidence that males are better athletes than females? Yes, scads. Do those advantages persist after hormone treatments? Scientists have looked into the matter, and yes,” stated the WaPo editors.

“Separate sports divisions exist to mitigate those biological gaps. It’s impossible to construct a coherent case for unfettered trans inclusion that fits those facts, without ultimately arguing for abolishing women’s athletics entirely.”