California billionaires tax trails in another poll days before election

California’s proposed billionaires tax is losing support days before Election Day, according to the second major independent poll released this week.

Thursday’s poll by the Institute of Governmental Studies at UC Berkeley found 42% of likely voters in favor of Proposition 40 and 50% opposed, with 8% undecided. In a mid-September Berkeley IGS poll, 45% of likely voters favored Proposition 40, while 42% were opposed and 13% were undecided. It would need majority support to pass.

The measure would impose a one-time, 5% tax on the wealth of California billionaires.

A pair of statewide measures aimed at blocking Proposition 40, Proposition 41 and Proposition 42, remained short of the needed majority support, with opposition mounting, the poll found.

Proposition 41 had support from 38% of likely voters while 47% were opposed and 16% were undecided, compared to IGS’ mid-September poll in which 37% were in favor, 33% opposed and 30% undecided. Proposition 42 support remained at 43% as it was in September, while opposition rose to 45% from 34% and undecided fell to 12% from 23% last month.

Both also require majorities to pass. If either passes and receives more “yes” votes than Proposition 40, it could prevent the wealth tax from taking effect if courts find the measures conflict.

“These results suggest that neither the advocates of the wealth tax nor those seeking to block future taxes have managed to persuade a majority of voters to their sides,” IGS Co-Director Eric Schickler said. “This may reflect an electorate unhappy with the wealth and power of billionaires but also not sold on a specific solution.”

The poll was conducted online in English and Spanish Oct. 19-25, 2026, among 2,787 registered voters, of whom a weighted subset of 1,477 had either already voted or were considered likely to vote in the state’s Nov. 3 election. The margin of error was plus or minus 3 percentage points for the subset of surveyed likely voters.

It is the second poll this week to find support for the Proposition 40 billionaires tax fading. A Public Policy Institute of California poll Tuesday found that support for Proposition 40 had fallen to 46% from 52% in a September PPIC poll, while opposition had risen to 52% from 46% last month. That poll also found support slipping and opposition mounting to Propositions 41 and 42, though it found Proposition 42 maintaining narrow majority support among likely voters.

Nearly $400 million has been spent collectively on the three measures, among the most closely watched contests on the state ballot.

Proposition 40 is sponsored by SEIU United Healthcare Workers West, which says it would help offset federal Medicaid cuts. It would impose a one-time, 5% tax, payable over five years with interest, on an estimated more than 200 Californians and certain trusts with a net worth — the total value of all assets and property interests worldwide — of $1 billion or more who lived in the state as of Jan. 1, 2026. Supporters include the California Nurses Association, independent Vermont U.S. Sen. Bernie Sanders and Rep. Ro Khanna, a Fremont Democrat.

Opponents include Gov. Gavin Newsom, the California Teachers Association and both candidates for governor — Democratic former Health Secretary Xavier Becerra and Republican former Fox News host Steve Hilton. They’ve said such a one-time, California-only tax wouldn’t provide recurring new funding and would drive wealthy innovators and job creators, hefty contributors to the state’s income tax revenues, to other states.

Proposition 41 would prohibit new state taxes that exempt their revenues from California’s spending limit and require audits of programs funded by new special taxes. Proposition 42 would prohibit new state taxes on the ownership of personal property, such as financial assets, and limit certain retroactive taxes.

While likely voters were cooling on the billionaires tax, support remained steady for Proposition 3, which would make permanent higher income tax rates on high earners that voters initially approved in 2012, then extended in 2016 until 2030. The higher rates kick in at incomes of $371,000 for single filers and $743,000 for joint filers, increasing the rate on income above those thresholds from 9.3% to 10.3%. The top rates, which increased to 12.3% from 9.3%, kick in at $743,000 for single filers and $1.5 million for joint filers.

The IGS poll found that support for Proposition 3 has held steady at 54% while opposition has edged up slightly to 37% from 34%, and 8% remain undecided.

Support for another statewide measure aimed at limiting local tax measures, Proposition 43, continues to trail opposition, the poll found. Proposition 43 would require two-thirds approval for local special taxes proposed through citizen initiatives, which currently can pass by a simple majority. Special taxes, which fund specific purposes, already require two-thirds approval when proposed by local governing bodies.

The IGS poll found that while support for Proposition 43 grew to 36%, opposition also grew to 46%. In September, 31% were in favor and 40% opposed.

While the poll focused on tax-related measures, it also asked about another closely watched initiative, Proposition 39, which would require voter identification. Support slipped to 37% while opposition grew to 57% with just 5% undecided. In September, 39% were in favor, 52% opposed and 9% undecided.

Proposition 4, which would repeal a state prohibition against public financing for election campaigns, had 41% support and 35% opposition in the latest poll.