Starting in 2018, Republican legislators, led by Idaho’s Barbara Ehardt, pushed laws banning transgender girls from participating in girls’ sports, citing alleged competitive advantages. These laws, supported by conservative groups like the Alliance Defending Freedom, spread to nearly 30 states and gained federal backing under the Trump administration, which revoked funding from schools allowing trans athletes to compete. However, scientific reviews show limited evidence that trans girls have athletic advantages, especially those on hormone suppressants. The Supreme Court recently heard cases challenging these bans, focusing on the legal definition of sex under Title IX rather than athletic fairness, signaling potential broad implications beyond sports.

The controversy echoes historical scrutiny of female athletes, with renewed policies enforcing biological sex verification and DNA testing to exclude trans women from competition. These measures, endorsed by major sports bodies and conservative activists, risk marginalizing both trans athletes and cisgender girls subjected to invasive verification. Critics warn that a Supreme Court ruling upholding these bans could legitimize wider discrimination against transgender people in employment, housing, and healthcare, while current policies already restrict trans youth’s access to sports and medical care, fueling a growing right-wing backlash under the guise of protecting women’s sports.