Key facts
- Sergey Brin, co-founder of Google, contributed at least $132 million to the campaign against Proposition 40, the report said.
- Former Google CEO Eric Schmidt gave more than $48 million to the opposition campaign, according to the report.
- The campaign against Proposition 40 raised nearly $425 million, according to campaign finance filings cited by the report.
- The pro-Proposition 40 campaign, sponsored by SEIU-United Healthcare Workers West, raised just more than $31 million, the report said.
- Proposition 42, which would ban any taxation on billionaire wealth, passed, according to the report.
- Rob Lalka of Tulane University compared the campaign to Uber and Lyft's 2020 ballot measure fight, where more than $200 million was spent.
California voters rejected Proposition 40, a proposed one-time 5% tax on billionaires, and passed Proposition 42, which would ban any taxation on billionaire wealth, according to a report published November 10, 2026. The report said Proposition 40 was poised to be defeated by double-digit numbers.
Tech industry donors raised nearly $425 million to oppose Proposition 40, according to campaign finance filings cited by the report, making it the most expensive opposition campaign in state history. Sergey Brin, the co-founder of Google, contributed at least $132 million, more than any other donor, the report said. Former Google CEO Eric Schmidt gave more than $48 million. Executives from Palantir, DoorDash, Stripe and Reddit and prominent venture capitalists also donated.
The campaign against Proposition 40 ran ads and mailers warning that the tax was dangerous and would hurt everyday people, with taglines calling it an "everyone tax," a "reckless experiment" and "you're next." Supporters said the money would fund the state's healthcare losses from Donald Trump's One Big Beautiful Bill Act, while opponents said it would make healthcare funding worse.
The pro-Proposition 40 campaign, sponsored by the union SEIU-United Healthcare Workers West, raised just more than $31 million, the report said, leaving it outspent nearly 14-fold. Suzanne Jimenez, the union's chief of staff, said: "All lies have a shelf life." She said billionaire-funded propaganda may mislead voters but that as hospitals reduce services and emergency rooms close, the truth will become harder to hide.
Counties that voted for Proposition 40 were typically more Democratic and include Los Angeles, San Francisco and other areas around the Bay Area, the report said. Counties that voted against it were mostly red, rural and poor, with up to 80% of voters there voting no, according to the latest count cited by the report.
Rob Lalka, a business professor at Tulane University, compared the campaign to Uber and Lyft's 2020 ballot measure fight, in which the companies spent more than $200 million to defeat an initiative over labor rights for drivers. Francesco Trebbi, a business and public policy professor at the University of California, Berkeley, said campaign funding has broken records nationwide this midterm cycle and pointed to Elon Musk giving $446 million to House and Senate races. Trebbi said more data and statistical evidence are needed to conclusively finalize the discussion.