California voters narrowly back billionaire tax in new poll

California’s explosive billionaire tax battle is tightening dramatically just weeks before voters decide whether to slap the state’s wealthiest residents with a one-time 5% levy on their fortunes.

A new UC Berkeley Institute of Governmental Studies poll, co-sponsored by the Los Angeles Times, found Proposition 40 clinging to a razor-thin advantage among likely voters — with 45% supporting the measure, 42% opposed, and a potentially decisive 13% still undecided.

That marks a noticeable slide from six weeks earlier, when the poll found 48% backing the proposal and 41% against it. 

The shift comes amid a massive advertising war over the measure, which has become one of the most closely watched fights on California’s packed Nov. 3 ballot.

Proposition 40 would impose a one-time tax equal to 5% of the net worth of billionaires who were California residents as of Jan. 1, 2026. The measure is designed primarily to raise money for healthcare programs amid anticipated federal funding cuts, with additional revenue earmarked for education and food assistance.

But the tax has triggered fierce pushback and opponents have poured huge sums into the campaign.

Mark DiCamillo, director of the Berkeley IGS poll, said voters appear concerned about economic inequality while remaining wary of an unprecedented tax targeting assets rather than simply income.

“When you’re going about taxing the billionaires’ assets, I mean that’s something kind of new and different, and it’s risky, and the governor’s against it,” DiCamillo told the Times, adding that many voters are approaching the proposal cautiously.

One California businessman is warning the measure could send wealthy residents racing for the exits. 

Eric Schiffer, chairman of family office Patriarch and CEO of Reputation Management Consultants, told Fox Business he believes its passage would create a “giant sucking sound” of entrepreneurs leaving California.

Schiffer, who said he works with billionaire clients, argued that some wealthy residents could decide the Golden State is no longer worth the price.

“Why would anyone stay if they have spent their life building wealth that they were already taxed on?” he told the outlet.

The proposed tax is also facing competition from two other ballot propositions that could effectively derail it.

Proposition 42, which would restrict taxes on certain forms of personal property and limit retroactive taxation, currently has 43% support, 34% opposition and roughly 23% undecided, according to the Berkeley poll.

Proposition 41, meanwhile, is even more unsettled. About 37% of likely voters support it, 33% oppose it and 30% remain undecided.

Both could have major implications for Proposition 40.

While the billionaire levy is fighting for every vote, another measure targeting affluent Californians appears to be on more comfortable footing. 

Proposition 3 would make permanent an existing income-tax increase on high earners that currently helps fund schools and healthcare. The tax, originally approved in 2012 and scheduled to expire in 2031, applies to individuals earning at least $360,000 annually.

The stronger reception for Proposition 3 highlights a key distinction confronting voters — extending an existing income tax versus creating a new levy on billionaire wealth.

The wealth tax has attracted national attention and enormous political spending, while exposing divisions among prominent California Democrats. The California Democratic Party has endorsed Proposition 40, while Gov. Gavin Newsom opposes it, citing concerns about its potential long-term effects on state finances.

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