At least 19 states now either bar or limit participation in sports by transgender athletes, who are at the center of a polarizing, politicized debate, even though only a fraction of them are believed to be among America's 8.5 million high school and college athletes.
Transgender athlete bans are being challenged in court and advocates on both sides are citing or pointing to Title IX, the landmark anti-discrimination law that has protected and helped girls and women since its passage in 1972.
