Billionaire donors back a ballot measure that would nullify California's wealth tax
Opponents of California's one-time 5% billionaire tax have raised more than $300 million, about ten times what its backers have. For the few hundred people in scope, residency was fixed on Jan. 1, 2026, so payment and a rival nullifying measure are what remain open.
The Board Room · Leadership desk
Key figures: opponents spending or booking roughly $96 million of airtime and digital messaging, against $209,000 by supporters, per AdImpact; opponents raised more than $300 million; 52% of likely voters said yes in a September poll; the tax applies to net worth over $1 billion.
| Figure | Value | Note | Claim |
|---|---|---|---|
| Opponents' airtime and digital ads, spent or booked, roughly | $96,000,000 | Supporters: $209,000, per AdImpact | 7 |
| Opponents raised, over | $300,000,000 | 1 | |
| Likely voters for yes | 52% | 6 | |
| Taxed net worth, over | $1,000,000,000 | 3 |
What happened
- Gov. Gavin Newsom, Planned Parenthood, the California Teachers Association and most Republicans have joined the tech and venture donors opposing Proposition 40.
- The state Democratic Party's executive board endorsed the measure earlier this year despite Newsom's opposition.
- A September Public Policy Institute of California poll found 52% of likely voters for the measure and 46% against.
- AdImpact data show opponents spending or booking about $96 million in airtime and digital messaging, against $209,000 from supporters.
- Most of the revenue from the one-time levy would go to replacing federal funding cuts to healthcare.
Why it matters
- Who has to decide decision For billionaires already counted, the choice before Nov. 3 is how they would raise cash for a possible 5% bill on their holdings, and which of the competing measures to fund.
- What it limits constraint A yes vote on Proposition 40 does not on its own guarantee collection, because a companion measure on the same ballot is written to void it.
- Who's exposed exposure Hospitals and clinics are invoked by both campaigns: the tax would fund replacement of federal healthcare cuts, and an opposition ad says lost revenue would force cuts to them.
- What it sets up precedent Passage would make California the first state to tax billionaires' net worth, the example any later state proposal would be compared with.
The measure counts billionaires living in California as of Jan. 1, 2026 [4]. That means the main personal decision came due before any ballot was mailed [7]. Google co-founders Sergey Brin and Larry Page began cutting ties with the state in anticipation of the tax [5]. For someone counted on that date, leaving this autumn does not change the bill if Proposition 40 passes. The levy falls on net worth, mostly held in investments for the ultra-wealthy, and not on pay [3].
Building a Better California, a committee, has drawn millions of dollars from Brin, from venture capitalist John Doerr and from former Google CEO Eric Schmidt [14]. It is backing other ballot measures that would nullify Proposition 40, including one to ban new taxes on financial assets and other personal property, excluding real estate [14]. That ban would restrict future state taxes on anyone in California who holds financial assets. That is a far larger group than the few hundred billionaires the wealth tax reaches [8]. The ABC News account does not say how the state would settle a conflict if both measures passed.
Money and opinion point in different directions. Brin alone accounts for close to $100 million of the opposition total [17], and on the reported tenfold gap the yes side has about $30 million [18]. In advertising the ratio is nearer 460 to one [19]. Even so, the September poll had yes six points ahead, with 2% giving neither answer [20]. Short of money, the yes campaign is leaning on Bernie Sanders [15]. "Are we destined to live in an oligarchic society begging for crumbs while our economic and political lives are controlled by a handful of the wealthiest people on Earth?" Sanders said at a California rally. "Brothers and sisters, that is the question on the ballot." [11]
The sharpest objection comes from Democrats on the no side. "We're not opposed to the concept of a wealth tax," said Jodi Hicks, CEO of Planned Parenthood's California chapter. "We just believe this proposal is seriously flawed and could do more damage than good." [10] Opponents argue the measure will drive wealthy people and their tax money out of California [21]. The state draws nearly half its personal income tax from its top 1% of earners [9]. Newsom has called for a national billionaire tax instead, arguing that a single-state version will not be effective and could hurt California's finances [12].
The timing undercuts that case. Opponents say the proposal is already driving wealthy people away [21]. If they are right, part of the budget damage they warn about has already happened, whatever the result. A no vote on Nov. 3 [15] would not restore ties already cut.
What to watch
- A public poll taken after September showing whether the six-point yes margin holds against roughly $96 million in opposition advertising.
- Any ruling or official guidance on how Proposition 40 and the ban on new financial-asset taxes would interact if voters approve both on Nov. 3.
- Further reported departures of California billionaires before the vote, the trend opponents say is already eroding the income tax base.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence62
- Adoption
- Not scored
- Hype gap+10
- Incentives85
- Confidence58
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
Opponents of the measure have raised more than $300 million, nearly a third of it from Google co-founder Sergey Brin, roughly 10 times the amount raised by the yes side.
- [2]
Opponents include Gov. Gavin Newsom, Planned Parenthood, the California Teachers Association and most Republicans, alongside tech moguls and venture capitalists who are putting up the majority of the money.
- [3]
Proposition 40 would impose a one-time 5% tax on the wealth of Californians whose net worth exceeds $1 billion, with most revenue dedicated to replacing federal funding cuts to healthcare; it would be the nation's first tax on the wealth of billionaires, targeting investments rather than simply raising taxes on paychecks.
- [4]
The tax would apply to billionaires living in the state as of Jan. 1, 2026.
- [5]
Some Silicon Valley tech moguls began cutting ties with the state in anticipation of the tax, including Sergey Brin and fellow Google co-founder Larry Page.
- [6]
In a September Public Policy Institute of California poll, 52% of likely voters said they would vote yes on the measure and 46% said they would vote no.
- [7]
With mail ballots being sent to voters, opponents are spending or booking roughly $96 million of airtime and digital messaging, compared with $209,000 by supporters, according to ad-tracker AdImpact.
- [8]
A few hundred billionaires live in California, according to the nonpartisan Legislative Analyst's Office.
- [9]
California relies on its top 1% of earners for nearly half its personal income tax revenue.
- [10]
"We're not opposed to the concept of a wealth tax," said Jodi Hicks, CEO of Planned Parenthood's California chapter. "We just believe this proposal is seriously flawed and could do more damage than good."
- [11]
"Are we destined to live in an oligarchic society begging for crumbs while our economic and political lives are controlled by a handful of the wealthiest people on Earth?" Sanders said at one of three recent California rallies. "Brothers and sisters, that is the question on the ballot."
- [12]
Newsom has largely opposed tax increases as governor and has called for a national tax on billionaires, arguing a single-state proposal will not be effective and could hurt California's bottom line.
- [13]
The state Democratic Party's executive board endorsed the measure earlier this year despite Newsom's opposition.
- [14]
Billionaires including Sergey Brin, venture capitalist John Doerr and former Google CEO Eric Schmidt have given millions to a committee called Building a Better California, which is fighting the tax and backing other ballot measures that would nullify it, including a proposal to ban new taxes on financial assets and other personal property, excluding real estate.
- [15]
The yes side includes some labor unions, Rep. Ro Khanna and Sen. Bernie Sanders, and with much less money is relying heavily on Sanders ahead of the Nov. 3 deadline to vote.
- [16]
In an ad funded in part by Building a Better California, doctors in white coats warn the measure will cost California revenue in the long run and force the state to cut funding to hospitals and clinics.
- [17]
Brin's contribution to the opposition is close to $100 million.
- [18]
The yes side has raised about $30 million.
- [19]
Opponents' ad spending and bookings exceed supporters' by about 460 to one.
- [20]
The September poll had yes ahead by six points, with 2% giving neither answer.
- [21]
Opponents say the measure will drive wealthy people and their tax money out of California, creating bigger budget problems, and are concerned the proposal is already driving wealthy people away.
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Sources
1 independent publisher whose own reporting we read for this story.
- abcnews.comTop Democrats join the wealthiest in fighting a California tax increase on billionaires
1 article · October 9, 2026
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Topics
- Ballot Measure Campaign FinanceFollow
- Wealth TaxationFollow
- California billionaire wealth taxFollow