Blue State Loses Even More Support

Support for California’s proposed billionaire tax has slipped in a new survey, raising fresh questions about Proposition 40 as voters prepare for the November 3 election.

The UC Berkeley Citrin Center for Public Opinion Research-POLITICO poll found 45% of likely voters supporting Proposition 40 and 43% opposing it, while 12% remained undecided.

That represents a decline from earlier polling cited by POLITICO, when support stood at 50%.

The narrowing margin comes as Californians hear competing arguments over taxes, government spending, health care funding and the potential economic consequences of targeting the state’s wealthiest residents.

What Is California Proposition 40?

Proposition 40 would impose a one-time tax of up to 5% on certain California taxpayers and trusts with covered assets worth more than $1 billion.

The tax would apply to assets including businesses, stocks and other securities, artwork, collectibles and intellectual property. Real estate and certain retirement accounts would be excluded.

According to California’s official voter guide, 90% of the money collected would go toward health care programs, while 10% would be used for food assistance or education-related programs.

State analysts estimate that the tax could generate tens of billions of dollars over several years. However, they also warn that California could experience an ongoing decline of less than $1 billion annually in income-tax revenue from billionaires, depending partly on how wealthy residents respond to the measure.

Opposition Is Stronger Among Voters Following the Issue Closely

One of the most notable findings in the new poll involves voters who say they have heard a great deal about Proposition 40.

Among those highly engaged voters, 57% said they opposed the measure while 38% supported it.

That finding could become important as both campaigns increase advertising and outreach ahead of Election Day.

Jon Cohen, founder and CEO of TrueDot, whose firm conducted the poll, told POLITICO that large amounts of campaign money are expected to be spent before voters make their final decision.

He also said that stronger opposition among voters already familiar with the proposal suggests the pro-Proposition 40 campaign could face challenges as public awareness increases.

Voters Question the “One-Time” Tax Promise

Proposition 40 is officially written as a one-time tax.

California’s voter guide states that a yes vote would authorize the state to collect a one-time tax from billionaires equal to 5% of their wealth, while a no vote would prevent the tax from taking effect.

Still, political opponents have focused heavily on concerns about whether California could pursue additional taxes in the future.

Advertising from opponents has argued that lawmakers could return with further tax proposals if the state faces future budget problems.

That argument goes beyond what Proposition 40 itself authorizes, but the new poll suggests perceptions about future taxation could influence some voters.

For older Californians and homeowners who closely follow state taxes and spending, that broader debate may become an important part of the campaign.

Other Polling Shows a Closely Divided Electorate

Not every recent survey produces the same result.

A September Public Policy Institute of California poll found 52% of likely voters supporting Proposition 40 and 46% opposing it after respondents were shown the official ballot title and label.

That survey also found large partisan differences.

Among likely Democratic voters, 72% supported the measure. Support fell to 46% among independents and 21% among Republicans.

PPIC also found that support for Proposition 40 declined considerably among older voters.

The differing results highlight an important reality about political polling: results can vary depending on when a poll is conducted, how questions are worded, which voters participate and how likely-voter models are constructed.

Undecided Voters Could Play a Major Role

The Citrin Center-POLITICO survey found that a meaningful share of voters still had not made up their minds.

Among undecided voters who indicated which direction they were leaning, 65% leaned toward supporting Proposition 40 while 15% leaned toward opposing it.

That leaves both campaigns with an incentive to compete aggressively for voters who have yet to reach a firm conclusion.

With weeks remaining before the November election, advertising about taxes, health care spending and California’s business climate could influence how those voters ultimately decide.

How Californians View Billionaires

The survey also examined voters’ broader attitudes toward billionaires.

According to the poll, 44% of respondents said billionaires do more harm than good, while 34% viewed them favorably.

Those attitudes could shape how voters interpret Proposition 40.

Supporters of the measure argue that extremely wealthy residents should contribute more toward public services.

Opponents argue that taxing wealth could encourage wealthy individuals and businesses to relocate, potentially reducing future tax revenue.

California’s Legislative Analyst acknowledges that behavioral responses from billionaires could affect state finances. Its official analysis estimates that the state could lose hundreds of millions of dollars or more in annual income-tax revenue depending on how affected taxpayers respond.

Gavin Newsom Opposes Proposition 40

California Gov. Gavin Newsom has publicly opposed Proposition 40.

That position puts him at odds with many Democratic voters, who continue to support the measure by substantial margins in recent polling.

The political disagreement is notable because Newsom remains a prominent national Democratic figure.

The Citrin Center-POLITICO poll suggested his opposition to the measure has created some tension among Democratic voters, although Cohen cautioned against interpreting the finding as evidence of a broader political collapse.

Instead, he described it as an issue-specific disagreement between Newsom and part of his political coalition.

Billions of Dollars Are Already Involved in the Campaign

Proposition 40 has attracted significant campaign spending.

California Secretary of State records showed more than $31 million in reported contributions supporting the measure through August 2, 2026.

Opposition committees had reported more than $11 million over the same period.

Those figures can continue to change as additional campaign finance reports are filed.

The amount of money being raised indicates that Proposition 40 is likely to remain one of California’s most heavily debated ballot measures ahead of November.

What Would Proposition 40 Do With the Money?

If approved, Proposition 40 revenue would primarily fund health care.

The official ballot summary states that 90% of the revenue would go toward health care programs, with the remaining 10% allocated to food assistance or education-related programs.

The measure would also exempt the revenue from some existing California constitutional requirements involving school funding, budget reserves and the state spending limit.

Those provisions have become part of the broader debate over how the money would be collected and spent.

Supporters and Opponents Make Different Economic Arguments

Supporters say California’s wealthiest residents can afford to contribute more and argue that Proposition 40 could provide substantial funding for health care and other public needs.

Opponents argue that a wealth tax could damage California’s economy, encourage affluent taxpayers to relocate and reduce future income-tax collections.

The state’s official voter guide presents arguments from both sides and confirms that economists expect both a large temporary increase in revenue and the possibility of lower ongoing income-tax collections from billionaires.

That makes Proposition 40 not simply a debate about taxing billionaires, but also a broader dispute over California’s tax policy, spending priorities and economic competitiveness.

Proposition 40 Vote Is Set for November 3

California voters will decide Proposition 40 during the November 3, 2026 general election.

The state will begin mailing ballots on or before October 5, and Election Day polls will be open from 7 a.m. until 8 p.m.

With recent polls producing different results, the electorate remains divided as the campaign enters its final stretch.

The Citrin Center-POLITICO survey was conducted online from September 8 through September 14, 2026, among 2,418 registered California voters. Its reported margin of error was plus or minus 2.7 percentage points.