California Gov. Gavin Newsom vetoed a bill late Friday night that would have required judges to consider whether parents have affirmed the gender identity of their children amid custody disputes.

Newsom argued that other politicians could use it as a strategy to “diminish civil rights of vulnerable populations.”

The bill, introduced by state Assemblywoman Lori Wilson , would allow courts to consider each parent’s affirmation of the child’s gender identity when making decisions about custody and visitation.

Wilson said the legislation, called the TGI (Transgender, Gender-Diverse and Intersex) Youth Empowerment Act, would require courts to recognize that the consideration of gender identity is in the best interest of the child, in case a parent were to oppose a legal name change process.

“As the mother of a trans child, it is jarring to know that TGI youth are at higher risk of depression, mental health crises, self-harm and suicide than their cisgender peers,” Wilson said in a statement.

“Family courts are required to consider a variety of factors when determining the best interest of the child … including the health, safety and welfare of the child, any history of abuse, and history of substance abuse,” she continued, “The TGI Youth Empowerment Act provides California the opportunity to take one step closer to building a safer, more dignified, and equitable world for TGI youth and their families.”

While Newsom said he shares the commitment of advancing transgender rights in Californians, he won’t support the bill because of its efforts to change legal standards for another branch of government.

“I urge caution when the Executive and Legislative branches of state government attempt to dictate — in prescriptive terms that single out one characteristic — legal standards for the Judicial branch to apply,” Newsom wrote in his veto letter.

California State Sen. Scott Wiener responded to the veto on X, the platform formerly known as Twitter, saying Newsom’s decision was a “tragedy for trans kids.”

“These kids are living in fear, with right wing politicians working to out them, deny them health care, ban them from sports & restrooms & erase their humanity,” his post said. “CA needs to unequivocally stand with these kids.”

Wiener followed up in a thread, saying the bill was surrounded by an astounding amount of “right wing misinformation.” He acknowledged that Newsom had been a “staunch ally to the LGBTQ community,” but called the veto “a mistake.”

Newsom vetoed two other bills on Friday night.

One bill would prohibit the California Department of Corrections and Rehabilitation from providing any information or responding to requests by the U.S. Immigration and Customs Enforcement. The other would have banned driverless testing and operations of heavy-duty self-driving cars.