Tech Leaders Spend $300 Million to Defeat California's One-Time Billionaire Tax

Google co-founder Sergey Brin, DoorDash founder Tony Xu, and several other technology executives have donated more than $300 million to defeat California Proposition 40. The measure would impose a one-time 5 percent tax on the assets of the state's billionaires. Supporters of the tax raised only $32 million by the time of the report.

David McCuan, a political science professor at Sonoma State University, identified the campaign as the most expensive ballot measure fight in state history. The spending disparity created a roughly 10 to 1 advantage for the opposition. The funds supported a large volume of television advertising, radio spots, and direct mailers aimed at registered voters.

The tax proposal originated from a group of academics, including Brian Galle, an economics professor at the University of California, Berkeley. Galle stated that some opposition flyers claimed the tax could apply to general retirement savings. He noted that those specific claims were not present in the original draft he helped write. Ashley Craig, a volunteer with the pro-tax group Patriotic Millionaires, reported that voters frequently expressed concern over alleged secret provisions that would tax everyone.

Mark Zuckerberg, the founder of Meta, did not donate directly to the opposition. However, Meta filings showed that he informed the company's board he intended to purchase a home outside the state to avoid the levy. The board subsequently created a new class of shares to allow him to pay the tax without affecting the company's stock price. The board includes Xu and Stripe co-founder Patrick Collison, both of whom funded the opposition.

Governor Gavin Newsom, who is considering a 2028 presidential run, opposes the tax. He described the measure as poorly written and warned that billionaires, whose estimated wealth totals 2.3 trillion dollars, might leave the state. Xavier Becerra, the gubernatorial candidate, and former congresswoman Katie Porter also backed the No side. The state Democratic Party endorsed the tax, though Craig said she received limited ground support from the party.

Opponents also funded two additional ballot measures. One would bar new state taxes on personal property or retroactive taxes, while the other would require state auditors to review proposed tax measures for financial impact before a vote. If either measure receives more votes than Proposition 40, it could negate the tax even if voters approve it.

A recent Public Policy Institute of California poll found that voters narrowly support the tax but also back the two measures designed to block it. Mark Baldassare, the institute's statewide survey director, noted that only about one-third of citizen initiatives pass. He planned to conduct another survey as voters received state guides explaining the measures. Suzane Jiminez, chief of staff at the SEIU health workers union, said 3,000 volunteers were knocking on doors and that Senator Bernie Sanders and Congressman Ro Khanna had rallied support across the state.