The California Legislature has overwhelmingly passed a measure requiring all presidential and gubernatorial candidates to release their tax returns to get on the primary ballot, which could shake things up for President Donald Trump in the 2020 election.

The Presidential Tax Transparency & Accountability Act, SB 27, would require that the candidates release the previous five years of their returns. The bill passed 57-17 in the Assembly on Tuesday and 29-10 in the state Senate Thursday. It now awaits the signature of Democratic Gov. Gavin Newsom to become law.

The measure includes an urgency clause, which would allow the legislation to take effect immediately, in time for the 2020 election, reports ABC-7 News. The measure only applies to the primary ballot because the state constitution allows political parties to nominate their own presidential candidates in the general election.

Trump promised during the 2016 campaign to release his tax returns, but refused after he was elected. Democrats in Congress have been unsuccessfully trying to pry loose his returns, suggesting Trump is hiding foreign payments, profiting from his elected office and cheating on his taxes.

Eighteen other states have legislation similar to California’s, but none has become law, according to a database tracked by the National Conference of State Legislatures. California, the most populous state, has more than 24 million eligible voters.

“Presidential candidates need to put their own interests aside in the name of transparency,” bill author, state Sen. Mike McGuire (D), said in a statement. “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.”

McGuire is confident the law would withstand a legal challenge, the San Francisco Chronicle reported.

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The California Legislature passed a similar measure in 2017, but then-Democratic Gov. Jerry Brown vetoed it. He said he hesitated “to start down a road that well might lead to an ever-escalating set of differing state requirements for presidential candidates.” Brown refused to release his own tax returns when he ran for governor in 2010 and 2014.

Newsom has not indicated whether he’ll sign the new measure. He was the first gubernatorial candidate in his race last year to release copies of his own federal tax returns.

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