California Senate Bill 27

California Senate Bill 27 (SB 27), alternatively known as the Presidential Tax Transparency and Accountability Act, is a California law that requires candidates running for either President of the United States or Governor of California to publicly release their tax return of the previous five years in order to be listed on the primary ballot. The bill, authored by State Senators Mike McGuire and Scott Wiener, was signed into law by Governor Gavin Newsom on July 30, 2019.
The law does not place the requirement to publicly release tax returns on candidates running as write-in candidates.
A similar bill was vetoed in 2017 by Governor Jerry Brown. In vetoing the bill, Brown cited the slippery-slope argument as well as his concern that the law would be struck down by the courts as unconstitutional.
Court challenges.
Within a week of the bill being signed into law, it was challenged in court. The Trump re-election campaign, the California Republican Party, and Judicial Watch all filed lawsuits challenging the constitutionality of the law. The suit by Judicial Watch is on behalf of four California voters.
On September 19, 2019, U.S. District Judge Morrison England issued a temporary injunction against enforcement of the law with a promise for a final ruling by the end of the month. In issuing the injunction, the judge made reference to the Ethics in Government Act as preempting the law under consideration.
On November 21, 2019, the California Supreme Court unanimously determined the law violated the California Constitution and that President Donald Trump must be allowed to appear on the March 2020 primary ballot. Chief Justice Tani Cantil-Sakauye delivered the 7-0 decision. The Attorney General of California is appealing the September ruling in a federal appeals court, with a decision expected after the March 2020 primary election.