Sergey Brin funds opposition to California billionaire tax

Google co-founder Sergey Brin has contributed over $100 million to opposition efforts against California’s proposed billionaire tax. Brin is the largest donor to the political advocacy group Building a Better California, which has raised approximately $187 million to block the measure and support pro-business policies.

Proposition 40, appearing on the November ballot, proposes a one-time 5% tax on the net wealth of billionaires residing in California as of January 1, 2026. The measure aims to direct 90% of the revenue to state healthcare programs and 10% to education, food assistance, and administration. For Brin, who has a net worth of nearly $260 billion, the tax could represent a liability of roughly $13 billion.

In addition to opposing Proposition 40, the opposition is funding Proposition 42, a constitutional amendment that would prohibit new taxes on financial assets. If Proposition 42 receives more support than the billionaire tax, it could potentially lead to legal challenges that stop the implementation of Proposition 40. Other prominent tech figures, including Eric Schmidt and John Doerr, have also provided significant financial support to the opposition.