Brin and Tech Donors Fund $300 Million Campaign to Block California Asset Tax

Sergey Brin, co-founder of Google, and other prominent technology executives have collectively donated more than $300 million to defeat a one-time 5 percent tax on the assets of California billionaires. This funding makes the contest for Proposition 40 the most expensive ballot measure fight in state history, according to David McCuan, a political science professor at Sonoma State University who tracks elections.

The opposition coalition includes Tony Xu, founder of DoorDash; Patrick Collison, co-founder of Stripe; Chris Larsen, co-executive chairman of Ripple; and venture capitalists John Doerr, Michael Moritz, and Vinod Khosla. In contrast, the group of supporters has raised only $32 million for the measure.

Mark Zuckerberg, founder of Meta, has not contributed personal funds to the opposition. However, Meta's filings with the Securities and Exchange Commission revealed that Zuckerberg told the board of directors, which includes Xu and Collison, that he would purchase a home outside the state to avoid the levy. The board subsequently created a new class of shares to allow Zuckerberg to pay the tax without affecting the company's stock price.

The volume of advertising and direct mail from both sides has created confusion among residents. Brian Galle, an economics professor at the University of California at Berkeley who helped draft the proposal, noted that a flyer he received claimed the tax could apply to general retirement savings. Galle stated that those specific provisions were not part of the original text he wrote.

Ashley Craig, a volunteer with the pro-tax group Patriotic Millionaires, said she frequently hears from voters who believe the measure contains hidden provisions to tax everyone. Any modifications to the tax structure would require a two-thirds majority in the state assembly and must remain consistent with the intent of the original measure.

Galle argued that the heavy spending demonstrates the exact inequality the tax seeks to correct. He stated, "The irony is that Prop 40 is meant to make democracy more equal, but the billionaires are using their money to avoid that," referencing the Supreme Court's decision in Citizens United v FEC. Francesco Trebbi, a professor at Berkeley's Haas School of Business, described the contest as "Sergey Brin v millions of Californians," arguing that the disparity erodes public trust in the system.

The campaign has exposed divisions within the Democratic Party. While the state party has endorsed the tax, Craig reported receiving limited ground support from the organization. McCuan described the vote as a proxy test between progressive and moderate factions. He noted that a victory could encourage progressive candidates to propose similar ideas in the 2028 presidential race. Governor Gavin Newsom, who is considering a 2028 run, opposes the tax, calling it "poorly written" and warning that it could harm the state if the estimated $2.3 trillion in billionaire wealth leaves. Gubernatorial candidate Xavier Becerra and former congresswoman Katie Porter also oppose the measure.

Opponents have also funded two additional ballot measures. One prohibits new state taxes on personal property or those applied retroactively, while the other requires state auditors to review the financial impact of proposed taxes before a vote. If either of these measures receives more votes than Proposition 40, it could negate the billionaire tax even if voters approve it.

A recent poll by the Public Policy Institute of California found that voters narrowly support the tax but also back the two measures designed to stop it. Mark Baldassare, the institute's statewide survey director, noted that only about one-third of citizen initiatives pass, placing the burden on the affirmative side. He plans to conduct another poll as voters receive state guides explaining the measures.

Suzane Jiminez, chief of staff at the SEIU health workers union, which sponsored the measure, expressed confidence in the outcome. She reported that 3,000 volunteers have recently knocked on doors and distributed flyers, and that Senator Bernie Sanders and Congressman Ro Khanna have rallied support across the state. McCuan suggested that even a defeat could benefit the backers, allowing them to blame moderates and target big tech as a political issue.