$300 Million War Chest Aims to Block California's 5% Asset Tax

California voters will face a historic spending disparity on the ballot this November as a one-time tax on billionaire assets goes to a vote.

The campaign against Proposition 40 has raised more than $300 million, a figure that David McCuan, a political science professor at Sonoma State University, identifies as the highest expenditure for a state or local ballot measure in history.

Supporters of the 5 percent tax have raised $32 million. The $268 million gap represents a spending ratio of roughly 10 to 1 against the measure.

The opposition includes prominent technology leaders and venture capitalists. Sergey Brin, co-founder of Google, Tony Xu, founder of DoorDash, and Patrick Collison, co-founder of Stripe, are among the major donors. Chris Larsen, co-executive chairman of Ripple, and investors John Doerr, Michael Moritz, and Vinod Khosla have also contributed to the anti-tax effort.

Mark Zuckerberg, founder of Meta, has not donated directly to the opposition. However, SEC filings indicate he informed the company's board, which includes Xu and Collison, that he plans to purchase a home outside the state to avoid the tax. The board subsequently created a new class of shares to help him manage the financial impact on Meta's stock price.

The massive advertising campaign has generated confusion among voters. Brian Galle, a Berkeley economics professor who helped draft the proposal, received a flyer claiming the tax could apply to retirement savings for anyone. Galle stated that those details were not in the original text. Ashley Craig, a volunteer with Patriotic Millionaires, reports hearing similar concerns from voters about secret provisions in the measure.

The financial disparity has drawn criticism regarding democratic equality. Galle noted that the billionaires are using their wealth to avoid the very outcome the tax seeks to achieve. He cited the Citizens United v FEC ruling as context for the influence of money in politics. Francesco Trebbi, a professor at Berkeley's Haas School of Business, described the contest as a fight between one wealthy individual and millions of residents, arguing it erodes trust in the system.

The issue has also created a divide within the Democratic Party. The state party endorses the tax, but ground support from party structures has been limited, according to Craig. Governor Gavin Newsom opposes the measure, calling it poorly written and warning that it could drive billionaires away. Gubernatorial candidate Xavier Becerra and former congresswoman Katie Porter also oppose the tax. McCuan views the vote as a test between progressive and moderate factions, noting that a win could inspire similar proposals in the 2028 presidential race.

Opponents are also funding two other ballot measures. One would bar new state taxes on personal property or retroactive taxes. The other requires state auditors to review the financial impact of proposed tax measures before voters decide. If either of these passes with more votes than Proposition 40, it could effectively negate the billionaire tax even if voters approve it.

A recent Public Policy Institute of California poll shows voters narrowly support the tax, but they also support the two measures designed to stop it. Mark Baldassare, the institute's statewide survey director, noted that only about a third of citizen initiatives pass, placing the burden of proof on the yes side. Suzane Jiminez, chief of staff at the SEIU health workers union, reported that 3,000 volunteers are currently distributing flyers and knocking on doors. Senator Bernie Sanders and Congressman Ro Khanna have also held rallies to support the measure.