With legal challenges pending over a new California law requiring presidential candidates to disclose their tax returns to appear on the ballot, the sponsor of a similar bill in Massachusetts said the Bay State should follow suit before waiting for the court cases to play out.

Sen. Michael Barrett, who filed a presidential tax returns bill in January for the second consecutive session, said the Legislature often passes laws that could be subject to a challenge in court, and in those cases they act on the bill and then "let litigants sue."

"I wish we had been the first," Barrett told the News Service. "It goes without saying that there's going to be pushback and that the president will sue, but that is helpful in its own way. You want to join the legal issues involved as soon as possible and get them before a court. That was always part of the plan for our bill as well."

Barrett's bill, filed with 31 cosponsors, would require presidential and vice presidential candidates to submit their tax returns and a statement of financial interest to state officials in order to appear on the Massachusetts ballot. Primary candidates would need to submit their returns for the three most recent available years, and general election candidates five years.

The returns would be posted on the secretary of state's website.

President Donald Trump has for years rebuffed requests to make his tax returns public, both as a candidate and while in office, despite the disclosure being common practice among recent past presidents.

Last month, the U.S. House Ways and Means Committee, chaired by Rep. Richard Neal, filed a complaint in federal court to obtain six years of Trump's tax returns. Neal has also tried to secure the returns by sending a written request to the Internal Revenue Service and issuing a subpoena to Treasury Secretary Steven Mnuchin.

California Gov. Gavin Newsom, a Democrat, signed a law on July 30 requiring candidates for president and governor to disclose five years of tax returns to earn a spot on the ballot in his state. The Los Angeles Times reported Tuesday that President Donald Trump and his campaign were challenging the law in federal court, and that other lawsuits, including ones involving the California and national Republican parties, had also been filed.

"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 wrote in his signing 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."

Trump's complaint argues that states cannot impose their own qualifications for federal office and calls the California law "a Partisan Effort" to obtain his tax information. The complaint said he disclosed "extensive information about his finances" during the 2016 campaign, including a financial disclosure of more than 100 pages.

"The Democratic Party is on a crusade to obtain the President's federal tax returns in the hopes of finding something they can use to harm him politically," reads the complaint, as posted online by the L.A. Times. "In their rush to join this crusade, California Democrats have run afoul of these restrictions on State power over federal elections."

Barrett, who first announced plans for his bill after the 2016 elections, said his motivation is "less about Trump and more about the principle." With the 2020 presidential race underway, Barrett said it's "easy to imagine" similar resistance to disclosure from other candidates.

The version of the bill Barrett filled last session was killed when the Democrat-controlled Election Laws Committee included it in a study order. The committee, newly chaired this session by Rep. John Lawn and Sen. Barry Finegold, has not yet held a hearing on the refiled bill (S 383).

Barrett thinks dynamics around the idea have shifted since last year.

"A few legislators in key positions at the time did not want to see Massachusetts be the test case, and it was also the case that a few legislators in key positions did not want to seem to legislate in a way that was primarily seen as anti-Trump, but things have changed," he said. "Legislators have now assumed new positions and some of the folks who hesitated are no longer playing the same roles, but it's also the case that the issue has become something important in its own right. This is no longer an anti-Trump idea, this is really a pro-transparency idea."

Were Massachusetts to require the disclosure of candidate's tax returns, Barrett said he believes the state would be on solid legal footing.

He pointed to a 1978 opinion to the Senate by the justices of the Supreme Judicial Court on legislation requiring that candidates and certain public officials file statements of financial interest with the Ethics Commission. Barrett said that opinion -- which found the bill did not violate privacy rights and would not add to the constitutional qualifications for public office -- addressed issues similar to those tied up in the California lawsuits.

"One thing I know for sure, if we don't legislate now, we're not going to have anything in place [before the 2020 election] because the courts are likely to come in at the 11th hour, leaving us no time to pass a statute should they vindicate California on every front, so prophylactically we should pass the statute and see what the courts do," Barrett said.