The Supreme Court, in a landmark decision on Tuesday, upheld laws from West Virginia and Idaho that restrict transgender female athletes from participating in girls’ and women’s sports teams. The 6-to-3 ruling has significant implications for 25 other states with similar laws.

These laws, endorsed by the Trump administration, focus on limiting the involvement of transgender athletes in sports. The administration directed federal agencies to withdraw funding from schools that permit transgender athletes to compete in girls’ and women’s sports.

The case has sparked public interest, drawing attention from Olympians and other elite athletes who have weighed in through legal briefs. Earlier, the International Olympic Committee decided to bar transgender athletes from competing in women’s Olympic events, mandating genetic testing for all participants. Additionally, the N.C.A.A. has prohibited trans women from taking part in women’s sports competitions.

Two students, Becky Pepper-Jackson from West Virginia and Lindsay Hecox from Idaho, challenged these state laws. These laws define participation in girls’ sports teams based on ‘biological sex,’ determined as a person’s birth sex.

The ruling highlights a strong ideological split within the court. The conservative majority concluded that states have the right to decide eligibility for women’s and girls’ sports based on biological sex.