TL;DR

Tech billionaires have poured over $120m into fighting California’s Proposition 40, a one-time 5% wealth tax on billionaires heading to the November ballot, against $31m raised by union backers. Sergey Brin leads with $82m and has moved assets out of state; Doerr, Moritz, Collison, Schmidt, Larsen, Thiel, and others follow. Donation figures come from campaign filings.

Silicon Valley’s wealthiest are spending heavily to stop California’s proposed billionaire tax, according to a tally of campaign filings. Opponents have poured more than $120m into sinking or blunting the measure, roughly four times the $31m raised by its union backers.

Proposition 40 would impose a one-time 5% tax on residents and trusts worth over $1bn when Californians vote in November. Sponsor SEIU-UHW says the levy on the state’s roughly 200 billionaires would fund healthcare, food assistance, and education, with proponents projecting $100bn in revenue.

Google cofounder Sergey Brin is the opposition’s single largest funder, giving $82m to a committee called Building a Better California. That includes a $16m cheque cut on 15 May, weeks before the ballot deadline.

Brin, whom Bloomberg’s index reportedly ranks the world’s third-richest person at $280bn, moved a raft of LLCs out of California before a key January deadline. He has compared the tax to Soviet socialism, telling The New York Times he does not want California to “end up in the same place” as the country his family fled.

Kleiner Perkins chairman John Doerr, who wrote Google’s famous first $12.5m cheque, is the second-biggest donor at $10m. Former Sequoia boss Michael Moritz has given $7.5m and Stripe chief Patrick Collison $7m, per the filings.

Former Google CEO Eric Schmidt, long an advocate of closer ties between tech and government, was the group’s earliest donor after Brin at just over $3m. Ripple executive chairman Chris Larsen, whose company is a founding partner in the Open USD stablecoin consortium, gave $2.5m plus $5m to a separate opposition group that Ripple matched.

The list runs on through Wonderful Company’s Stewart Resnick ($2.5m), DoorDash CEO Tony Xu ($2m), Affirm’s Max Levchin ($1m), and Wicklow Capital’s Daniel Tierny ($500,000). Angel investor Ron Conway gave $100,000 to another group after failing to persuade Governor Gavin Newsom to broker a deal that would have kept the measure off the ballot.

The AI subtext

Peter Thiel, whose Founders Fund just raised $6bn for AI bets, took a different route. He gave $3m in December to the political arm of the California Business Roundtable, and The New York Times reports he is spending more time in Argentina.

The fight is inseparable from the AI boom that has swollen the fortunes now under threat, with Brin still central to Alphabet’s AI strategy. Building a Better California has also pushed rival ballot questions designed to blunt the tax if it passes.

Supporters argue billionaires enriched partly by public investment can afford a one-off levy to patch gutted health budgets. Opponents warn of capital flight, valuation chaos, and years of litigation, and Brin’s pre-deadline LLC moves suggest the flight has already begun.

This is a tech elite more used to gathering on Necker Island than fighting ballot measures. November will show whether $120m can buy a majority.