Google Co-Founder Sergey Brin Donates $100M+ to Fight Billionaire Tax

The latest donation brings Brin's personal spending on the campaign to more than $100 million, according to campaign finance records. Build a Better California, an advocacy group with an associated political action committee, was founded with $35 million in seed money from Brin, former Google CEO Eric Schmidt, and other billionaires.

Proposition 40, which voters will decide on Nov. 3, would impose a one-time 5% tax on the worldwide wealth of California residents with a net worth exceeding $1 billion. The measure, sponsored by the labor union SEIU United Healthcare Workers West, is projected to raise about $100 billion for healthcare programs, food assistance, and public education.

The union offered to withdraw the 5% proposal if Governor Gavin Newsom backed a smaller 2% tax through the legislature, but Newsom rejected the offer. In a Substack post, Newsom said he supports a federal wealth tax, arguing that billionaires can easily relocate to lower-tax states.

Several groups, including Planned Parenthood and the California Medical Association, have criticized the tax as a flawed response to federal funding cuts. The California Teachers Association argued it would not provide stable school funding and could drive wealthy residents out of state.

Brin, who moved to Nevada, would face a $13.3 billion tax bill under Proposition 40, based on his $267 billion net worth. Other tech figures, including Mark Zuckerberg, Travis Kalanick, Peter Thiel, and Larry Page, have also left California in recent years.