By G9ija

A federal appeals court heard arguments Monday over a law banning transgender athletes from competing in girls’ and women’s sports, an issue that has become highly politicized in the United States.

Three judges of the 9th US Circuit Court of Appeals in California examined the case challenging a law passed last year in the western state of Idaho.

Idaho was the first US state to pass legislation banning transgender athletes from taking part in girls’ or women’s sports, but similar bills are at various stages in around 20 other Republican-ruled states.

The plaintiff in the landmark case is Lindsay Hecox, a 20-year-old transgender student-athlete at Boise State University who is barred by the law from competing on the women’s track and field team.

But after a district court blocked the Idaho bill, sending it to the appeals court in California, cisgender track athlete Madison Kenyon signed on as a party in the case, to ask that the law be upheld.

“Women’s sports exist precisely because there are real, physical differences between the sexes,” her lawyer Christiana Holcomb, with the conservative group Alliance Defending Freedom, told the virtual court hearing Monday.

“Males naturally have insurmountable athletic advantages over females” that cannot be undone by treatment to reduce levels of the muscle-building hormone testosterone, she argued, in support of a blanket ban.

“These physical differences mean that it is unfair to force young women to compete against biological males.”

However, Hecox’s lawyer said Monday that testosterone levels are “the primary driver of athletic performance differences between men and women,” and that the Idaho bill had used a deliberately “narrow” definition of biological sex for its blanket ban.

The Idaho law would “exclude trans women and girls — and only trans women and girls — from sports altogether,” as forcing them to compete as boys would “be so substantially disruptive to who they are” it would “violate the core of their being.”

The Idaho law, which applies to female teams at public schools and colleges, allows anyone to play for male teams.