California Gov. Gavin Newsom (D) signed a controversial bill Tuesday that would all but force President Donald Trump to give in to longstanding demands that he release his tax returns.

“As one of the largest economies in the world and home to one in nine Americans eligible to vote, California has a special responsibility to require this information of presidential and gubernatorial candidates,” Newsom said in a statement.

“These are extraordinary times and states have a legal and moral duty to do everything in their power to ensure leaders seeking the highest offices meet minimal standards, and to restore public confidence. The disclosure required by this bill will shed light on conflicts of interest, self-dealing, or influence from domestic and foreign business interest.”

Newsom’s decision comes just weeks after the California legislature overwhelmingly approved the measure, which requires all presidential and gubernatorial candidates to release their tax returns in order to appear on the primary ballot.

Though Newsom has repeatedly called on Trump to release his tax returns, it’s been unclear whether he would sign the legislation or follow in the footsteps of his predecessor. When the state legislature passed a similar bill in 2017, then-Gov. Jerry Brown, another Democrat, vetoed it, saying he was hesitant to “start down a road that well might lead to an ever-escalating set of differing state requirements for presidential candidates.”

Political insiders have also warned that while Newsom approving the measure would raise his national profile and appease his base, it could also stir discontent among the blue state’s Republicans and loosen Democratic holds in some counties.

The bill’s author, state Sen. Mike McGuire (D), has made it clear that the measure was designed to nettle Trump.

“Presidential candidates need to put their own interests aside in the name of transparency,” he said in a statement earlier this month. “So far, our current president has done the opposite. It’s time that President Trump steps up, stops with the obstruction, and follows through with 40 years of time-honored tradition that has made this nation’s democracy stronger.”

Trump, the first president in four decades to not release his tax returns, has already shown that he plans to fight any attempt at obtaining those financial disclosure documents. Last week, he sued both New York state officials and the House Ways and Means Committee over Democrats’ efforts to force their release.

“I hope it’s constitutional,” Sen. Dick Durbin (D-Ill.) told reporters of the California law, referencing the inevitability of Trump suing over it.

This story has been updated with comment from Dick Durbin.