Tech billionaires flood California campaign to kill wealth tax

Building a – Sergey Brin, John Doerr and other major tech and finance billionaires have poured more than $120 million into opposition to a proposed California billionaire wealth tax—a one-time 5% levy on state residents and trusts with assets above $1 billion—while unions

California’s billionaire tax fight is no longer just a policy debate. It has turned into a high-dollar campaign sprint—one where some of the richest people in tech and finance are trying to change the outcome before voters ever see the measure.

This November, Californians will vote on whether to impose a billionaire tax after a last-minute push for Gov. Gavin Newsom to broker a deal failed to materialize. With a one-time 5% wealth tax on state residents and trusts with assets over $1 billion potentially on the line—and with some backers facing the prospect of a lengthy court battle—major figures from Silicon Valley have moved fast and spent big.

So far. the opposition has drawn more than $120 million from some of the biggest names in technology. finance. and venture capital through political spending aimed at outright sinking the tax or complicating its path. By comparison, SEIU-UHW, the healthcare workers union and the proposal’s primary backer, has received roughly $31 million thus far.

The largest single check has come from Google cofounder Sergey Brin. The billionaire. who moved assets out of the state ahead of a key deadline in January. has continued to fund the opposition. Through a political committee called “Building a Better California,” Brin has donated $82 million in total so far. His most recent donation—$16 million—was cut on May 15, just over a month before the deadline for finalizing ballot initiatives. Bloomberg’s estimates put Brin’s worth at $280 billion, making him the world’s third-richest person.

John Doerr. the Kleiner Perkins chairman and an early investor closely tied to Google’s rise. has also been among the top donors. Doerr famously wrote Kleiner Perkins’ $12.5 million check for a stake in Google. He has donated $10 million to “Building a Better California,” making him the group’s second-largest donor after Brin. Doerr stepped down from the venture capital firm in 2016 but remains chairman, and he also serves on Alphabet’s board. Bloomberg estimates Doerr’s net worth at $15.6 billion.

The opposition includes other heavy hitters from payments and crypto. Chris Larsen. who cofounded OpenCoin in 2012—later renamed Ripple Labs. a blockchain financial infrastructure company—has donated $2.5 million to “Building a Better California.” Larsen stepped down as Ripple CEO in December 2016. but he remains executive chairman. In 2018, Larsen made history as the first person to join Forbes’ 400 richest list with a fortune primarily comprised of cryptocurrency. Bloomberg estimates Larsen is worth $12.4 billion.

Larsen has also put money behind Golden State Promise, a group outright opposing the tax, contributing $5 million. Ripple has donated an additional $5 million to that same effort.

Michael Moritz. a venture capitalist who stepped down from Sequoia Capital in 2023 after joining the firm in the 1980s. has donated $7.5 million to “Building a Better California.” Moritz was an early investor in Google and PayPal and helped make Sequoia one of Silicon Valley’s leading firms. A Welsh native, he was knighted by Queen Elizabeth II in 2013. Forbes estimates Moritz’s worth at $8 billion.

Payments startup cofounder Patrick Collison has also joined the effort. Collison, who cofounded Stripe alongside his brother John, donated $7 million to “Building a Better California.” Forbes estimates Collison is worth $16.3 billion.

Eric Schmidt—Google’s ex-CEO—has likewise contributed to the opposition. Schmidt has donated $3,026,176.51 to “Building a Better California,” described as the earliest donor to the committee after Brin. Bloomberg estimates Schmidt’s worth at $58.7 billion.

Peter Thiel. PayPal cofounder and a major political figure in recent years. has sent money that aligns with the broader effort to stop the tax. Thiel backed away from political spending after the 2022 midterms. but in January he made one of his largest donations since then to a group looking to stop the billionaire tax. In December 2025, Thiel donated $3 million to the political arm of the California Business Roundtable. The donation was not explicitly aimed at stopping the tax. but the longtime industry group is one of many lined up against it.

Thiel has also gone further than some other California billionaires in personal choices and reported travel time. The New York Times reported in May that Thiel is spending more time in Argentina. Bloomberg estimates Thiel is worth $22.1 billion.

Agribusiness wealth is represented too. Billionaire Stewart Resnick and Lynda Resnick bought California farmland in 1978 as a hedge against inflation. Today. Wonderful Company estimates that nearly half of all Americans buy products the firm grows. harvests. bottles. and packages each year. Stewart Resnick has donated $2.5 million to “Building a Better California.” Wonderful Company’s brands include Fiji Water. Pom Wonderful. Wonderful Pistachios. and Wonderful Halos. and the company owns roughly 180. 000 acres of California farmland. Forbes estimates Stewart Resnick’s worth at $5.4 billion.

DoorDash CEO Tony Xu has also donated to the opposition. Xu. who cofounded the delivery service alongside three of his Stanford classmates. has donated $2 million to “Building a Better California.” When DoorDash IPOed in 2020. Xu instantly became a billionaire. Forbes estimates his worth at $1.8 billion.

Max Levchin. CEO of Affirm and a prominent figure in the so-called “PayPal Mafia. ” has put money toward the opposition as well. Levchin cofounded what later became PayPal in 1998 and has donated $1 million to “Building a Better California.” In 2014. Levchin started Affirm. which went public in January 2021. Affirm’s total market cap is roughly $28 billion. Forbes estimates Levchin’s worth at $2.5 billion.

Some of the opposition effort has also relied on political coordination that goes beyond writing checks. Tech investor Ron Conway has spent decades working behind the scenes in Silicon Valley and is described here as pushing for Gov. Gavin Newsom to kill the proposed wealth tax before it reaches voters. In March. Conway told Jack Altman— the youngest brother of OpenAI CEO Sam Altman—that he was working to get Newsom to negotiate and stop the tax before it reached the ballot. That effort proved unsuccessful.

“Our job is to get Gavin to negotiate this so that it doesn’t get to the ballot. ” Conway told Jack Altman during an episode of Altman’s “Untapped” podcast. Conway has donated $100,000 to Stop the Squeeze, a political group that is outright opposing the proposed tax. Altman publicly thanked Conway for helping aid his return to the AI startup following Altman’s brief ouster in 2023. It is unclear what Conway’s net worth is. He was an early investor in Airbnb and GitHub, among other companies.

The campaign also includes Daniel Tierny, who leads Wicklow Capital, a family office venture firm he founded in 2013. Tierny cofounded the Global Electronic Trading Company (GETCO) in the 1990s after cutting his teeth as an options trader in Chicago. Wicklow Capital focuses on investments in “ABCD,” AI, blockchain, climate, and democracy. Tierny has donated $500,000 to “Building a Better California,” and he is one of 10 people to have donated to the group. It is unclear what Tierny’s net worth is.

What ties these efforts together is the tight calendar: a November vote, an attempt by backers to get Gov. Gavin Newsom to broker a deal that failed to materialize. and a ballot timeline that Brin’s most recent $16 million check hit just after. Brin’s asset move ahead of a January deadline underscores how quickly the opposition thinks the threat could become real—and how determined major donors are to stop it from ever reaching voters. even as the union’s campaign remains far smaller so far.

For now. the proposal’s fate sits with what voters decide this November. and with whether the legal and political fight has time to change its shape before that moment. But the money already on the table shows who expects the tax to be a direct risk—and who is willing to spend to keep it from becoming law.

California billionaire tax wealth tax Sergey Brin Building a Better California John Doerr Eric Schmidt Peter Thiel Tony Xu Max Levchin Ron Conway Daniel Tierny SEIU-UHW