Support for California’s One‑Time Billionaire Tax Drops to 42% Amid Massive Opposition Funding

California voters have reduced their backing for Proposition 40, the proposed one‑time 5% levy on the state’s wealthiest individuals, from a narrow majority of 52% to just 42% as the campaign entered its final days.

The shift comes as a coalition of technology magnates and other high‑net‑worth donors has poured more than $379 million into a coordinated effort to defeat the measure. The money is being used for television ads, digital outreach, and grassroots mobilization aimed at persuading undecided voters that the tax could jeopardize jobs and economic growth.

Proposition 40, first introduced in 2021, would have required a single, 5% surcharge on the net worth of California residents with assets exceeding $1 billion. Proponents argued the windfall could fund affordable housing, education, and climate initiatives, while opponents contended it would drive capital out of the state and set a precedent for punitive taxation of wealth.

The latest polling, conducted by a nonpartisan university research center, indicates that public opinion is now split, with 42% in favor, 45% opposed, and the remainder undecided. Analysts attribute the decline in support to a surge in advertising that frames the tax as a punitive measure that could trigger a broader exodus of tech firms and venture capital.

State officials have not yet disclosed whether the tax will appear on the ballot, but the governor’s office has signaled openness to revisiting the concept in future legislative sessions. If Proposition 40 is ultimately rejected, lawmakers may explore alternative revenue streams, such as adjustments to corporate tax rates or new fees on high‑income earners, to address the state’s ongoing budget shortfalls.