The US Supreme Court has ruled that states can forbid biological males from competing as females in school and college sports. US President Donald Trump hailed the ruling as a “big win.”

In a unanimous verdict on Tuesday, the court’s nine justices concluded that state bans on transgender athletes competing in female sports do not violate Title IX, a 1972 law forbidding sex-based discrimination in education.

“The Constitution and Title IX do not require an overhaul of women’s and girls’ sports throughout America,” wrote conservative Justice Brett Kavanaugh, who authored the ruling. Forcing women and girls to compete against males would “deny equal opportunity to female athletes because, as all agree, females and males have inherent physical differences.”

The court’s three liberal justices agreed that the bans do not violate Title IX, but argued that they violate the constitution’s 14th Amendment, which guarantees equal protection under the law. In her partial dissent, Justice Sonia Sotomayor quibbled that the ruling applied “a diminished view of equal protection” to women’s sports.

The court’s three liberal justices agreed that the bans do not violate Title IX, but argued that they violate the constitution’s 14th Amendment, which guarantees equal protection under the law. In her partial dissent, Justice Sonia Sotomayor quibbled that the ruling applied “a diminished view of equal protection” to women’s sports.

The ruling concerned two cases, in which transgender athletes challenged bans in Idaho and West Virginia. In Idaho, a male runner identifying as female argued that the state’s Fairness in Women’s Sports Act violated his 14th Amendment rights; in West Virginia, a male high-school student argued that the Save Women’s Sports Act violated his Title IX rights by banning him from competing in multiple sports.

Before the cases came before the Supreme Court, two appeals courts sided with the transgender complainants. The West Virginia teenager, Becky Pepper-Jackson, went on to win a state shot put title last month, beating his nearest female competitor by two feet.

With the passage of the Fairness in Women’s Sports Act in 2020, Idaho became the first state to ban males from female school and college sports. Twenty-six state legislatures followed suit, and Trump made the issue a key pillar of his 2024 campaign. Last year, Trump signed an executive order stripping federal funding from schools and colleges that allow males to compete against females.

Trump applauded the Supreme Court’s ruling. “BIG WIN,” he wrote on his Truth Social platform. “The United States Supreme Court just RULED AGAINST MEN PLAYING IN WOMEN’S SPORTS. Wow! That takes that ridiculous situation off the table!!!”