Sergey Brin donates $102 million to fight California billionaire tax

October 3, 2026 at 06:18 PM2 min

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Google co-founder Sergey Brin has donated $102 million to oppose California's Proposition 40, a proposed one-time 5% tax on billionaires. The measure, on the November ballot, could cost Brin about $13 billion. Campaign filings show opposition spending has exceeded $187 million, far outpacing the $32 million raised by supporters.

Key Facts

Sergey Brin has donated $102 million to Building a Better California, a PAC opposing Proposition 40.
Proposition 40 would impose a one-time 5% tax on California's 200 billionaires, with 90% of revenue going to the state's health care program.
Brin, with a net worth of nearly $260 billion, could owe about $13 billion if the measure passes.
Opposition spending against the tax has exceeded $187 million, while supporters have raised about $32 million.
California Governor Gavin Newsom has joined tech billionaires in opposing the measure, arguing it would reduce investments in education and public services.

Campaign Spending

Brin's $102 million contribution to Building a Better California makes him the largest sole contributor to the opposition effort. Total spending to block the tax has exceeded $187 million, according to campaign filings. Contributions supporting the measure have reached about $32 million.

Proposition 40 Details

Proposition 40 would impose a one-time 5% tax on California's 200 billionaires. Ninety percent of the revenue would go to the state's health care program, with 10% allocated to education, food assistance, and administration. Brin, with a net worth of nearly $260 billion, could owe about $13 billion under the tax.

Opposition and Relocation

Former Google CEO Eric Schmidt and PayPal co-founder Peter Thiel have also donated to organizations opposing the measure. Brin compared the proposal to his socialist Soviet upbringing, stating he fled socialism in 1979 and does not want California to end up in the same place. Governor Gavin Newsom argued the tax would erode the state's tax base and reduce investments in education, teachers, librarians, childcare, firefighting, and police. Brin now lists Nevada as his residence, and Google co-founder Larry Page has converted several assets out of California, including his family office Koop, incorporated in Delaware in December 2025.