California Voters Defeat Proposition 40, a Tax on Billionaire Wealth

California voters defeated Proposition 40, a proposed one-time tax on billionaire wealth, in the state's General Election on November 3, 2026, according to The Guardian.

The measure would have applied a one-time 5% tax to California residents whose net worth, the total value of what a person owns minus what they owe, was above $1 billion as of January 1, 2026. The money would have gone to healthcare programs, along with some education and food assistance. The measure was sponsored by SEIU-United Healthcare Workers West. Senator Bernie Sanders and Congressman Ro Khanna backed it.

Opposition came from several directions. California Governor Gavin Newsom opposed the measure, as did both the Democratic and Republican candidates for governor and Planned Parenthood Affiliates of California.

The campaign was the most expensive ballot campaign in California state history. Opponents spent nearly $425 million against the measure, which the Guardian described as the most expensive opposition campaign in the state's history. Google co-founder Sergey Brin contributed at least $132 million to the opposition, according to campaign finance filings. Those filings also showed opposition spending passing $2.5 million per day during the first two weeks of October. Donors to the opposition included executives from Google, Palantir, DoorDash, Stripe and Reddit.

Two other measures on the same ballot bore on the tax directly. Proposition 41 specifically targeted Proposition 40. Proposition 42 would limit certain new taxes and ban any tax on billionaire wealth. Under the rules, if either Proposition 41 or Proposition 42 received more yes votes than Proposition 40, it would stop the billionaire tax from taking effect, even if Proposition 40 had passed.

Voting in California is largely conducted by mail. Each active registered voter receives a ballot in the mail, and the state has more than 23 million registered voters. Mail ballots for the November 3 election had to be postmarked on or before Election Day and received by November 10, 2026. County elections officials could begin opening vote-by-mail envelopes up to 29 days before Election Day, and they must begin reporting results to the Secretary of State no more than two hours after they start tallying votes once polls close. Voters have until November 25, at 5:00 p.m., to correct signature problems on their ballot envelopes. The Secretary of State will certify the election results on December 11, 2026.