The Price of Not Being Taxed: Inside the $166 Million Campaign Against Prop 40
The Million Dollar Question: Building a Better California, the coalition fighting California’s billionaire tax, has raised roughly $166 million. How much of that went to the committee actually named “No on Prop 40”?
A) Nearly all of it B) About half C) About $20 million D) None of itRead on for the answer.
On November 3, Californians vote on Proposition 40, a one-time 5% tax on the net worth of the state’s billionaires. This is a look at what the opposition to it actually costs, where that money goes, and why the most consequential spending is not on the measure everyone is arguing about.
What it is
Proposition 40 would charge a one-time tax equal to 5% of net worth to people who were California residents on January 1, 2026 and whose net worth exceeded $1 billion. According to the Legislative Analyst’s Office, the tax would be assessed on wealth as of the end of 2026, due in 2027, with the option to spread payments across five years at additional cost. Real estate, pensions and retirement accounts are generally excluded. Ninety percent of the proceeds must go to health care; the remainder to education, food assistance, and administering the tax itself.
The measure is sponsored by SEIU-United Healthcare Workers West, and its stated purpose is to backfill health-care funding lost to federal cuts. The California Budget & Policy Center frames the revenue as a response to the Medicaid reductions in the 2025 federal reconciliation bill.
Two things about the design matter more than the headline rate. First, it applies to a very small group — the LAO puts it at “a few hundred people,” and most public accounts settle on roughly 200 California billionaires. Second, it is retrospective in an unusual way: residency is fixed at a date that has already passed, which means leaving the state in 2026 does not, by the measure’s own terms, get you out of it.
That second feature is what makes the fight over it so expensive. A tax you can avoid by moving is a nuisance. A tax you cannot avoid by moving is a bill.
Who is paying to stop it
Almost all of the organized opposition money runs through one committee: Building a Better California, co-founded by Google’s Sergey Brin and former Google chief executive Eric Schmidt.
Its donor list, compiled from Secretary of State filings downloaded through August 29, 2026 by the Fullerton Observer, reads like a slice of the Bay Area’s founding class:
| Donor | Contribution |
|---|---|
| Sergey Brin, Google co-founder | $122 million |
| John Doerr, Kleiner Perkins chair | $15.5 million |
| Chris Larsen, Ripple co-founder | $10.5 million |
| Patrick Collison, Stripe CEO | $7 million |
| Michael Moritz | $5.5 million |
| Eric Schmidt, former Google CEO | $3 million |
| John Hering, VP Capital | $946,000 |
| Stewart Resnick, Wonderful Company | $500,000 |
| Daniel Tierney, Wicklow Capital | $500,000 |
| Neil Mehta, Greenoaks Capital | $250,000 |
Total raised: $165,696,000. One person supplied roughly three-quarters of it.
The other side is funded very differently. The “Yes on 40 — Billionaire Tax Now — No on 41 & 42” committee had raised about $31.4 million as of the same date, and essentially all of it came from union treasuries and member dues: $22 million from SEIU, $7.3 million from the United Healthcare Workers West Political Issues Committee, $2 million from the SEIU-UHW West PAC.
That is roughly five dollars of opposition money for every dollar in support — before counting a separate $10.45 million committee funded by Chris Larsen and Ripple Labs, and smaller committees tied to the California Business Roundtable, whose own top donors include Peter Thiel at $3 million.
The asymmetry is worth sitting with, because it is not really an asymmetry of wealth. It is an asymmetry of concentration. SEIU-UHW represents more than 120,000 health-care workers, and its $31 million is assembled from dues paid in small increments by people who will never be affected by the tax one way or the other. The opposition’s $166 million comes from ten identifiable individuals, four of whom face nine- or ten-figure bills if it passes. Diffuse benefits and concentrated costs is the oldest asymmetry in politics; a ballot measure aimed at 200 people is close to its purest expression.
Why they spend it
Here is the arithmetic that explains everything else.
Fortune has reported that Brin would owe roughly $13 billion if the measure passes. He has put about $122 million into defeating it. That is a little under 1% of the exposure — the kind of ratio that, in any other context, would be described as an unusually cheap insurance policy.
Run the same math across the coalition and it holds. Bloomberg’s billionaire index put Schmidt’s fortune at about $58.1 billion; 5% of that is roughly $2.9 billion. His $3 million contribution is about a tenth of a percent of the bill.
This is the part of political spending that gets described in the wrong register. Nine-figure campaign contributions are usually reported as extravagance — proof of how much money there is at the top. Read against the liability, they look like something much more ordinary: a hedge with an expected return so lopsided that not making it would be the strange decision.
There is a second motive that is harder to price. California has roughly an eighth of the country’s population and a disproportionate share of its very large fortunes. A wealth tax that survives a first contact with voters here becomes a template everywhere else. Several donors and their allies have made the precedent argument publicly. Defeating Prop 40 is not only about $13 billion; it is about whether the next twelve states have a working model to copy.
How the money actually gets spent
This is where the campaign stops looking like a normal ballot fight.
Of the $165.7 million Building a Better California raised, only about $20.5 million went to “No on Prop 40,” the committee formed to argue against the measure directly. The rest went somewhere else:
- $63.3 million to the Yes on 41 campaign
- $64.3 million to the Yes on 42 campaign
Propositions 41 and 42 are the coalition’s own measures, qualified for the same ballot. Neither one is titled anything about billionaires.
Proposition 41 requires a pre-election audit of any program funded by a voter-initiated special tax, plus recurring audits every four years for special taxes enacted after January 1, 2026 — audits that must recommend cutting the program’s costs by at least 10% a year. It also bars new state taxes from being excluded from California’s constitutional spending limit, which is precisely the exclusion Prop 40 writes for itself.
Proposition 42 prohibits any new state tax on the ownership of personal property — financial assets, investment and retirement accounts, business interests, intellectual property, vehicles, jewelry, art. Real estate is not covered. It also prohibits new state taxes applied retroactively based on past conduct or status, and it states that conflicting measures on the same ballot are void.
The reason this matters is a quirk of California’s constitution that most voters never encounter. As the LAO puts it, if Proposition 41 or 42 receives more yes votes than Proposition 40, then Proposition 40 “could be stopped from becoming law even if it gets yes votes from a majority of voters,” because courts could find the measures in conflict.
So the campaign has two paths to victory. It can persuade Californians to vote no on a tax on 200 people — historically a hard sell. Or it can persuade them to vote yes, enthusiastically, on auditing government programs and protecting retirement savings, and let the conflicting-measures rule do the rest.
The advertising follows the same logic. Building a Better California has reserved roughly $87 million of television time. Mail arrives under committee names like “Californians Against Wasteful Spending and Higher Taxes, A Project of the California Business Roundtable” — technically disclosed, practically unsearchable, since typing that string into the Secretary of State’s committee lookup returns nothing.
What it costs, in context
$166 million is a large number that means little without comparison.
By Ballotpedia’s accounting, California’s 2020 Proposition 22 — the gig-work measure funded by Uber, Lyft and DoorDash — drew a combined $224.6 million and was the most expensive ballot measure in state history at the time. The 2022 sports-betting pair, Propositions 26 and 27, together drew $463.3 million.
Against those, Prop 40’s opposition is expensive but not unprecedented. What is unusual is the concentration. Prop 22 was funded by four large companies protecting a business model. This is one man supplying $122 million of $166 million.
Some other ways to hold the number:
- Across all of Building a Better California’s committees, the spend works out to roughly $830,000 per California billionaire who would be covered by the tax.
- Set against the LAO’s estimate that the measure “probably would collect tens of billions of dollars,” the opposition budget is well under 1% of the revenue at stake.
- Fortune reported that California’s 15 richest billionaires had put more than $336 million into state and federal elections during 2026, with Brin, Marc Andreessen, Ben Horowitz and Larsen accounting for $331 million of it. The Prop 40 fight is roughly half of that, in one state, on one ballot.
Hidden costs and tradeoffs
Money is the cheap part. The rest is messier.
Moving does not necessarily work. Brin and fellow Google co-founder Larry Page left California before the January 1 residency cutoff and have since assembled roughly $225 million of Miami real estate, according to Fortune. Whether that timing is enough is a question the Franchise Tax Board and, in all likelihood, the courts would settle. Residency disputes at this scale are slow, document-heavy, and rarely tidy.
The coalition is not unified. The New York Post reported, and Fortune followed up on, a rift between Schmidt and Brin over how the shared money is being deployed. An adviser told Fortune that Schmidt’s “only current involvement in politics is his contributions to defeating the billionaires tax” — and that his frustration came from those contributions also funding measures aimed elsewhere, including an unrelated environmental-review proposition. When a $166 million war chest funds a strategy of indirection, some of the donors will not have signed up for the indirection.
The messengers carry their own history. A key strategist for the campaign is Ned Wigglesworth, who two decades ago worked as a campaign-finance reformer. In 2005, Fortune reports, he warned about wealthy interests with “enough at stake to spend 150 million bucks” defending their turf, and wrote in a 2007 column that donors “give because they get.” He now runs the opposition. He did not respond to Fortune’s requests for comment.
Spending is visible. Every contribution above $100 is public and searchable at Cal-Access. The strategy of routing money through neutrally-named committees works on voters who do not look; it does not work on reporters, and the coverage it generates is itself a cost.
What people get wrong
That the opposition is only billionaires. It is not, and this is the single most misread fact of the campaign. Per CalMatters’ voter guide, Prop 40 is also opposed by the California Teachers Association, the California Medical Association, Planned Parenthood Affiliates of California, the California Professional Firefighters, and the State Building and Construction Trades Council — along with Governor Gavin Newsom. Their objections are about design, not principle: they say they were not consulted, that a one-time revenue spike does not fix a structural Medi-Cal shortfall, and that carving the money out of the constitutional school-funding formula sets a bad precedent. Meanwhile the measure is backed by the California Democratic Party, which endorsed it at 61.7% over Newsom’s objection, along with Bernie Sanders, Ro Khanna, Teamsters California and AFSCME California.
That it is an “everyone tax.” Mailers from the California Business Roundtable have argued that the “so-called billionaire tax is really an everyone tax,” pointing to a filing provision. The Fullerton Observer checked it: under the measure, Californians who are not billionaires simply certify on their return that they hold less than $1 billion in assets. Roughly 200 households pay the tax.
That anyone knows what it would raise. Three credible estimates are in circulation and they do not agree. The measure’s authors project about $100 billion over five years. The LAO says “tens of billions,” and adds a possible ongoing loss of less than $1 billion a year in income-tax revenue if billionaires leave. Researchers at the Hoover Institution put the initial take closer to $40 billion. All three are defensible; the spread reflects genuine uncertainty about asset valuation and behavioral response, not bad faith.
That a wealth tax is easy to assess. The headline is simple — 5% of net worth — but net worth at this level is mostly illiquid and mostly estimated. A founder’s fortune is typically a large block of stock in one company, plus private holdings with no market price, plus interests held through partnerships and trusts. Public estimates of the same person’s wealth routinely differ by billions between Forbes and Bloomberg, and neither has access to the actual balance sheet. The measure’s exclusion of real estate, pensions and retirement accounts adds a further line-drawing problem. This is a genuine administrative challenge rather than a talking point, and it is part of why the LAO builds tens of millions of dollars in annual administration costs into its analysis.
That the polling settles it. A Berkeley Institute of Governmental Studies survey in August found 48% support and 41% opposition among likely voters, with about 70% of Democrats in favor and 80% of Republicans against. A seven-point lead two and a half months out, against an $87 million advertising reservation, is not a safe lead. Ballot measures typically lose support as opposition advertising lands.
Bottom line
The answer is C. Of the roughly $166 million Building a Better California has raised, only about $20.5 million went to the committee named “No on Prop 40.” Roughly $128 million went to Propositions 41 and 42 — an audit measure and a personal-property-tax ban, neither of which mentions billionaires — either of which can void Prop 40 by simply out-polling it.
That is the real finding here, and it generalizes past California. The visible campaign is an argument about whether taxing 200 people is fair. The expensive campaign is a procedural maneuver most voters will never notice they participated in. At this level, money does not usually buy the argument; it buys the terms on which the argument is settled.
And the price of not being taxed, on the evidence of the filings so far, is roughly a penny on the dollar of exposure. Whether it works will be known on November 3.
All campaign-finance figures are from California Secretary of State filings as compiled through August 29, 2026, and will continue to move before the election. Current totals are public at Cal-Access.
Related reading:
- Taxing the Billionaires: Wealth-Tax Debates From California to Warren — the policy argument this ballot measure puts to an actual vote.
- Campaign Donors: Money in Modern Politics — how large political giving is structured, disclosed, and routed.
- Billionaire Politics: When Personal Wealth Becomes Public Power — the wider pattern this fight belongs to.
- Billionaires Flood Miami: Wealth Migration and the New American Geography — where Brin and Page went, and why timing matters.
- Net Worth Is Not Net Worth: How Billionaire Fortunes Evaporate on Paper — why assessing 5% of a fortune is harder than it sounds.
