Democratic 2020 candidate Sen. Elizabeth Warren came out Thursday against a proposed bill in Arizona that would limit girls’ sports to biological females.

Republican state Rep. Nancy Barto’s proposed bill would bar biologically male athletes who identify as transgender girls from competing in girls’ sports. The bill comes as biological males who identify as transgender have racked up victories in girls’ and women’s sports.

“Trans athletes are not a threat,” Warren wrote on Twitter Thursday. “We need to protect trans kids — and all LGBTQ+ kids — and ensure they feel safe and welcomed at school.”

“I urge the Arizona legislature to reject this cruel bill,” the Massachusetts senator added.

Trans athletes are not a threat. We need to protect trans kids—and all LGBTQ+ kids—and ensure they feel safe and welcomed at school. I urge the Arizona legislature to reject this cruel bill. https://t.co/9ALVjeIBiv — Elizabeth Warren (@ewarren) February 20, 2020

Every Democratic presidential frontrunner supports the Equality Act, which would force public schools to expand female athletic teams to include biological males who identify as transgender girls.

The House passed the bill in May 2019 with unanimous Democratic support.

Transgender athletes have piled up achievements in women’s sports. A biologically male marathon runner is set to compete in the USA Olympic trials as a woman later in February. (RELATED: We Spoke With This Former Olympian About Transgender Athletes. Here’s What She Said)

Biologically male cyclist Rachel McKinnon won a women’s cycling world championship and set a women’s world record in October 2019.

June Eastwood, a biologically male runner at the University of Montana who identifies as transgender, was named the Big Sky Conference’s female athlete of the week that same month. Eastwood previously competed on the university’s men’s cross country team.

Franklin Pierce University runner CeCe Telfer won an NCAA DII women’s track championship in May 2019. Like Eastwood, Telfer previously competed on the men’s team before switching genders.

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