David Zimmerman writes for National Review Online about an unusual step from California’s left-of-center governor.

Deviating from his past legislative support of transgender youth in California, Democratic governor Gavin Newsom vetoed a bill that would have required parents to demonstrate affirmation of their child’s gender identity in custody court battles.

Under California Bill AB957, judges would have been legally obligated to specifically consider whether parents have affirmed their child’s gender identity or gender expression in determining “the health, safety, and welfare of the child.” The California State Assembly passed the bill along strictly party lines earlier this month, hoping to advance transgender rights in the state.

Newsom said in a statement late Friday night he appreciates “the passion and values” of Democratic assembly member Lori Wilson for authoring the bill but disclosed he couldn’t sign it.

“I share a deep commitment to advancing the rights of transgender Californians, an effort that has guided my decisions through many decades in public office,” Newsom wrote.

“That said, 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,” he added. “Other-minded elected officials, in California and other states, could very well use this strategy to diminish the civil rights of vulnerable communities.”

Nonetheless, the California governor noted judges are still “required to consider a child’s health, safety, and welfare” in the context of their gender identity when hearing out parents in child custody cases, even if the bill wasn’t signed.

“Moreover, a court, under existing law, is required to consider a child’s health, safety, and welfare when determining the best interests of a child in these proceedings, including the parent’s affirmation of the child’s gender identity,” he concluded.

Following the governor’s veto, Wilson expressed her disappointment with the decision.