California Attorney General Rob Bonta joined 12 Democratic attorneys general on Tuesday, submitting an amicus brief opposing a legal challenge to Minnesota’s policies that allow transgender athletes to participate in female sports.

The brief was submitted to the U.S. Court of Appeals for the 8th Circuit in Female Athletes United v. Ellison. The case challenges Minnesota’s statewide policy permitting transgender athletes to compete in female sports.

The brief argues that Title IX’s prohibition on sex discrimination includes discrimination based on gender identity. It said excluding transgender athletes would violate the statute.

The amicus brief notes that courts have repeatedly held that policies inclusive of transgender students are consistent with Title IX’s language, which forbids exclusion “on the basis of sex.”

“Granting FAU’s motion would needlessly deny transgender student-athletes something that their cisgender female classmates take for granted: the ability to participate on an athletic team at school with their friends consistent with their lived identity,” the brief stated.

In May, advocacy group Female Athletes United filed a lawsuit against the Minnesota Attorney General Keith Ellison and other state officials, alleging that Minnesota’s transgender sports policy violates federal laws like Title IX of the Education Amendments of 1972.

“Female Athletes United is attempting to use a misinterpretation of Title IX to justify discrimination against transgender youth,” Bonta said in a press release. “We will continue to fight against unlawful attacks on transgender and other LGBTQ+ individuals’ rights whenever and wherever they occur.”

The brief also cites a 2022 survey where 62.6%of transgender youth respondents reported being “teased, bullied, or treated badly” at school in the previous year. More than 55% of such youths reported being victimized specifically due to their sexual identity, gender identity or gender expression, the brief cited.

Transgender youth continue to face “discrimination that harms their physical and mental health, and negatively impacts their academic performance,” the brief states.

In filing the amicus brief, Bonta joins the attorneys general of Washington, Connecticut, Hawaii, Illinois, Maine, Maryland, Massachusetts, Nevada, New York, Oregon, Rhode Island and Vermont.