2026-11-01 · contested story
Prop 40 billionaire tax draws over $300M in opposition as polls turn negative
California's Proposition 40 — a one-time 5% tax on the net worth of the state's roughly 200-250 billionaires, designed to raise an estimated $100 billion primarily to backfill federal Medicaid cuts — has become the most expensive ballot measure fight in state history. Billionaires led by Google co-founder Sergey Brin have poured more than $300 million into opposing it and funding two competing measures (Props 41 and 42) that could nullify it, while the SEIU-United Healthcare Workers West union and progressives like Bernie Sanders and Ro Khanna backed it with roughly $32-40 million. The fight split Democrats: Governor Gavin Newsom opposed it (preferring a national billionaire tax), while the state Democratic Party endorsed it. Polls showed support sliding from a slim majority in September to underwater (46% vs 52%) by late October. Mark Zuckerberg's SEC-disclosed deal to restructure Meta shares to pay the tax and stay in California became a flashpoint cited by both sides.
How each side frames it
left
"Despite throwing a massive, and expensive, fit over the proposed billionaire's tax, some of California's wealthiest seem to be staying put."
"Just to be clear, these "snowflake billionaires" are whining, wailing, and donating money to fight a tax that would effectively require them to part with one-eighth of the wealth they've gained since January 1, 2025."
"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?"
"We can either be a Democratic Party that stands for the working class in the tradition of the New Deal, or we can continue to cater to the donor class."
"Here, Gavin Newsom is literally siding with Sergey Brin, Peter Thiel and Elon Musk, Trump supporters, because they don't want to be taxed."
center
"If I was a California voter and I didn't have any training in economics or anything like that, I would be very confused. I would not really know what to think."
"California could lose roughly $1 billion to $3.5 billion a year in income tax revenue due to its shrinking billionaire population, the paper's authors estimated."
"There's going to be some kind of economic consequences, and whether you think those consequences are good or bad, and how bad you think they are, depend upon what you value."
"This is really not about Prop 40... but rather about trying to "re-balance the scale a little bit.""
"Among 105 respondents, 69.5 percent opposed the proposal, including 71.0 percent of economists and 85.0 percent of accountants. Lawyers were more supportive, with 60.0 percent favoring the tax."
right
"Silicon Valley billionaires left the state, taking their wealth and future wealth with them... These business tycoons are running to states like Florida and Texas because of lower taxes, economic freedom and future economic prosperity."
"the permanent loss of future income-tax payments from departing billionaires could end up costing California far more than the wealth tax ever collects."
"Read that carefully again. It says that at any time in the future, the legislature can lower the tax threshold from $5 Billion to $1 Million or $100,000 or $50,000 or $35.20 or whatever without going back to the taxpayers."
"France should not be sending California tax advice. It should be sending a warning."
"And what they ultimately want isn't a one-time tax on the rich, but heavy ongoing taxation to eliminate success."
What each side left out
The left left out — covered by the CBS News & Business Insider & The Daily Economy & TechCrunch
- The Stanford/Hoover estimate that the tax could produce a net fiscal loss (~$39B present value) due to lost future income taxes
- The valuation/administrative difficulties of taxing illiquid private company stakes and voting control
The left left out — covered by the TaxProf Blog & Yahoo Finance
- That ~70% of surveyed tax economists/accountants would vote against the measure
The right left out — covered by the otherwords.org & Fortune & Common Dreams
- That billionaires' effective state income tax rate was only ~0.26% of wealth annually (Zucman/Saez)
- That Nvidia's Jensen Huang and Tom Steyer support the tax and call paying it a 'privilege'
- That Zuckerberg ultimately struck a deal to stay in California and pay
The right left out — covered by the Truthout & Democracy Now! & BBC
- The healthcare rationale — ~3 million Californians at risk of losing Medi-Cal coverage from federal cuts the tax would backfill
The center left out — covered by the The Lever & Salon & Democracy Now!
- The partisan/donor-capture critique of Newsom's opposition as self-interested
- The framing of the fight as fundamentally about oligarchy and democracy
What's actually true?
[verified] Proposition 40 would impose a one-time 5% tax on the net worth of Californians worth more than $1 billion who resided in the state as of January 1, 2026.
[verified] Supporters estimate the tax could raise about $100 billion, with roughly 90% directed to healthcare and the rest to education and food assistance.
[contested] Stanford/Hoover economists Jaros and Rauh estimate the tax would collect only about $28-36 billion and project an average net loss of ~$38.9 billion once lost future income taxes are counted.
[verified] Google co-founder Sergey Brin has contributed more than $100 million (about $102 million) to oppose Prop 40, the single largest opposition donor.
[verified] Mark Zuckerberg struck a deal with Meta's board to create a new class of non-voting shares he can sell to pay the tax, committing to stay in California for eight years.
[verified] Opponents (Building a Better California) raised more than $300 million (reported totals of $304M-$333M) to fight Prop 40 and fund competing measures Props 41 and 42.
[verified] Late-October polling (PPIC and Citrin-Politico) showed Prop 40 falling below majority support, dropping from ~52% in September to 46% in favor versus ~52% opposed.
[verified] If Prop 41 or Prop 42 passes and receives more votes than Prop 40, the billionaire tax could be blocked even if voters approve it.
The narrative clash
How much revenue the tax would raise
Left: Proponents calculate that the state will gain about $100 billion.
Right: the Stanford researchers estimated the measure would collect roughly $40 billion—less than half the proponents' headline $100 billion figure.
Whether the tax causes net revenue gain or loss for the state
Left: the mythical threat of the wealthy packing their bags has been shown to be largely that—threats and a myth.
Right: a Hoover Institution study estimates a thirty-eight billion dollar net loss. Stuart Varney argues that billionaires are already fleeing the state to protect their wealth.
Whether billionaires are actually leaving California
Left: California actually has increased billionaires since Proposition 20... We've gone from 240 billionaires to 261 billionaires. Eighty-five percent of the venture capital has come into California.
Right: Eight California billionaires have reportedly already left the state: Larry Page, Sergey Brin, Mark Zuckerberg, Peter Thiel, Don Hankey, David Sacks, Jan Koum, Andy Fang, and Travis Kalanick.
Whether the tax is genuinely one-time
Left: Prop. 40 would only levy the tax once... pushing an additional tax through the Legislature would face daunting political and legal hurdles.
Right: Saez... has admitted it isn't a "one-time tax" as the measure proponents claim. Saez said: "I'm not there to pretend that it's once and never again."
Net fiscal effect — does the tax actually fund anything?
Left: It raises roughly $100 billion, with about 90% going to healthcare.
Right: Departing billionaires take future income-tax payments with them, so the state likely ends up poorer than if it had done nothing.
114 sources analyzed
Daily Kos Al Jazeera Democracy Now! Reason Magazine City Journal Mother Jones Business Insider TaxProf Blog RealClearMarkets City Journal The American Prospect CBC CNBC Investor's Business Daily Fox News Common Dreams CNN Tax Foundation New York Post City Journal Salon Capital & Main CBS News Boston Herald Fox News HuffPost NBC News Macau Business Manhattan Institute City Journal Mother Jones Politico Pacific Research Institute Fox Business Fox News The Daily Beast Los Angeles Times otherwords.org Richmond Times-Dispatch Washington Examiner Common Dreams CNN Bloomberg Government News Boston Herald City Journal The Daily Beast PBS NewsHour The Daily Economy National Post Fox News Mother Jones The Guardian Straight Arrow Boston Herald National Review Salon The Mercury News Pasadena Star News Investor's Business Daily Fox News Common Dreams The Washington Post The American Action Forum Boston Herald Salon PBS NewsHour KQED Investor's Business Daily Mother Jones PBS NewsHour Seoul Economic Daily Orange County Register Salon WIRED BBC Investor's Business Daily Common Dreams PBS NewsHour FlowingData The Telegraph The Daily Beast Sacramento Bee Truthout Common Dreams U.S. News & World Report The Lever The Daily Beast SFGATE CalMatters San Francisco Chronicle CNN KTVU CNN MyNorthwest.com Yahoo Finance TechCrunch Le Monde.fr The Capital Times Independent Institute The San Francisco Standard Billionaires.Africa Mises Institute Newsroom | UCLA Yahoo Ynetnews Annenberg Media The Times of India Americans for Tax Reform AOL.com Noozhawk Fortune Finshots EdSource The Mendocino Voice