California’s Proposition 40, which would impose a one-time 5% tax on billionaire wealth, is drawing a closely divided response from voters ahead of the November election. A new UC Berkeley Institute of Governmental Studies poll found 48% of likely voters support the measure, while 41% oppose it and 11% remain undecided.
The poll surveyed 4,207 registered voters in California from Aug. 3 to Aug. 9, including 2,310 likely voters. Mark DiCamillo, the poll’s director, said support below 50% at this stage is a warning sign, noting that undecided voters in California often end up voting against a measure.
Under the proposal, the tax would apply to California residents who were billionaires as of Jan. 1, 2026, and would be paid when 2027 tax returns are filed. Taxpayers could also spread payments over five years with 7.5% annual interest.
Backers say the money would help fund health care, education and food assistance programs at a time when federal health spending is being reduced. Support is strongest among Democrats, at 70%, while 80% of Republicans oppose it; among independents, support is 50% and opposition is 39%. The measure is being pushed by the SEIU-UHW West health care union and the California Democratic Party, while Gov. Gavin Newsom, some unions and billionaire groups are opposed.
