Politics

California voters face Proposition 40, a one-time billionaire tax

The Guardian reports opponents have spent upwards of $356m through committees to defeat Proposition 40.

Updated Nov 2, 2026 · 13:14 UTC4 reports

The short version

Californians will vote on Proposition 40, a one-time 5% tax on billionaires living in the state as of January 1, 2026.[The Guardian]
Tech billionaires have spent upwards of $356m in committees opposing the measure, and Sergey Brin has contributed at least $102m.[The Guardian]
Governor Gavin Newsom opposes the tax, arguing it would drive a race to the bottom and stifle innovation.[The Guardian]
The sponsoring union, SEIU-UHW, announced 1.55m signatures, nearly double the amount needed to qualify the measure.[The Guardian]

Proposition 40 would levy a one-time 5% tax on billionaires living in California as of 1 January 2026, with proceeds funding healthcare programs, along with some education and food assistance.[The Guardian]
Opponents have put upwards of $356m into independent expenditure-only political action committees to stop the measure.[The Guardian]
Google co-founder Sergey Brin has contributed at least $102m to the Building a Better California Super Pac, more than any other donor.[The Guardian]
Governor Gavin Newsom has opposed the billionaire tax, repeatedly arguing it would drive a race to the bottom and stifle innovation.[The Guardian]
SEIU-UHW announced it had gathered 1.55m signatures by the end of April, nearly double the amount needed to qualify for the ballot.[The Guardian]

The 1.55m signature figure is the union's own announced total, and the article does not present it as an independently verified count.[The Guardian]
Whether the tax would drive wealthy residents out of California is unresolved; Newsom's warnings are stated arguments, not established outcomes.[The Guardian]

Outlet counts describe coverage, not independent confirmation. Reports may share a wire service or original source.