Tech billionaires are adding to their already huge spending spree on California politics as campaigns for governor and a proposed wealth tax heat up. According to recently released campaign finance disclosures, big names pouring millions into state politics include current and former chief executives from Google, DoorDash, Reddit, LinkedIn and Facebook – evidence of Silicon Valley’s increasing involvement in politics.
Google’s former CEO Eric Schmidt has become a major donor, contributing $1.04m to an independent committee, the California Business Roundtable, that is campaigning against the proposed Billionaire Tax Act, according to new filings released by the state government. The union-backed tax proposal, opposed by almost all of the state’s mega-rich, aims to help cover education, food assistance and healthcare programs.
New campaign filings also reveal that Google co-founder Sergey Brin has donated to both Republican and Democratic candidates for the California governor’s seat, playing both sides of the aisle. Brin contributed $39,200 last week to Republican candidate Steve Hilton, a former Fox News contributor who served as an adviser to former British prime minister David Cameron. Hilton, also a billionaire, is married to Google’s former head of communications Rachel Whetstone.
Brin has also bankrolled Democratic candidate Matt Mahan, a Silicon Valley favorite among the crowded field of Democrats. Last month, Brin maxed out the limit for individual campaign donations for Mahan, at $78,400. On Monday, Brin handed a $1m donation to an independent committee working to elect Mahan called Deliver for California.
Brin, who relocated to a $42m estate on the north-eastern shore of Lake Tahoe in Nevada after the billionaire tax proposal, contributed $20m in January to a committee combating the measure, Building a Better California. Schmidt donated $2m to the same committee around the same time.
A notoriously private person, Brin has become increasingly involved in politics in 2026, as has the rest of Silicon Valley. He attended a White House dinner with Donald Trump last year, where the president called his girlfriend, wellness influencer Gerelyn Gilbert-Soto, a “really wonderful Maga girlfriend”. Brin’s former wife is Nicole Shanahan, who was Robert F Kennedy Jr’s running mate for president in 2024.
Mahan, who went to college with Meta’s CEO, Mark Zuckerberg, and is seen as the tech-friendly candidate, has been able to garner millions in donations from Silicon Valley since announcing his campaign at the end of January. New campaign filings from the state show he’s recently received individual donations of $39,200 from DoorDash’s CEO, Tony Xu, and LinkedIn co-founder Reid Hoffman. And he brought in the max of $78,400 from Reddit’s CEO, Steve Huffman, Cruise co-founder and former CEO Kyle Vogt, Napster co-founder and former Facebook president Sean Parker and Zynga’s founder, Mark Pincus.
In the last round of campaign filings, Mahan even courted donors who helped launch companies known for working with the Trump administration, including the Palantir co-founder Joe Lonsdale and Anduril co-founder Matt Grimm. Like Brin, Lonsdale has also donated to Hilton.
The battle over the billionaire tax has seen a steady flow of funding coming from the tech world too. Campaign filings show donors to Building a Better California include DoorDash CEO Xu ($2m), crypto billionaire and Ripple CEO Chris Larsen ($2m) and Stripe CEO Patrick Collison ($2m). Those who’ve donated to the California Business Roundtable include Palantir co-founder Peter Thiel ($3m), Ring founder James Siminoff ($100,000) and Larsen ($750,000).
Both Mahan and Hilton have publicly said they oppose the proposed billionaire tax, which is still in the signature-gathering phase to get on the November ballot. Campaign organizers said in a statement on Wednesday that they’ve been “working around the clock” to collect those signatures.
Brin and Schmidt didn’t immediately return requests for comment.
