Last summer, Elizabeth Prelogar, then a partner at Cooley, was living in Idaho when a federal judge there ordered in-person arguments in a lawsuit challenging the first state law to ban transgender athletes from playing school sports.

“It was serendipity,” said James Esseks, director of the American Civil Liberties Union’s LGBT and AIDS project who recruited a Cooley team, including Prelogar, to assist in its challenge to the Idaho law.