California Billionaire Tax Has Qualified for the Ballot. Newsom Has One Week to Kill It.

Since California's billionaire tax qualified for the November ballot — covered in our June 18 report — the story has shifted from petition drives to political survival. The June 25 deadline for initiative measures to be certified for the ballot is now seven days out as of Thursday, June 18, and Governor Gavin Newsom is in full pressure-campaign mode.

Where Things Stand

SEIU-United Healthcare Workers West submitted 1.55 million signatures in April, according to Business Insider. Nearly double the 874,641 required, the state must verify the validity of that threshold by June 25. The signatures passed. The question now is whether SEIU-UHW president Dave Regan can be persuaded to pull the measure before the clock runs out.

Newsom is reportedly trying to broker a deal with Regan directly. According to the Sacramento Bee, one of Newsom's closest advisors, Jim DeBoo, described the political situation with unusual bluntness at a California Chamber of Commerce event: "It's a unique time in California politics where one person [Regan] has managed to align the business community, the medical community, the billionaire community, all against one entity."

The California Teachers Association, Planned Parenthood Affiliates of California, and several other labor groups that typically move in lockstep with progressive Democrats have all come out in opposition. Their stated concern, according to Business Insider, is that a one-time tax does not provide sustainable long-term funding for schools or healthcare.

The Case for the Tax

There's a real funding problem. SEIU-UHW argues the tax is the only available mechanism to offset federal healthcare cuts signed by President Trump. Backers, including U.S. Sen. Bernie Sanders and Rep. Ro Khanna of Fremont, put the revenue estimate at roughly $100 billion. Opponents dispute that figure sharply.

The straightforward case is this: Washington has cut healthcare funding, the state faces a gap, and California had over 200 billionaires who could be affected by the tax as of January 1, according to Business Insider. The California Democratic Socialists of America and the Teamsters California are publicly backing it. If Regan walks away from a November vote, he walks away from the only near-term lever his union has.

The Case Against It

Newsom's office put its objection on the record with Newsweek: the governor "has been clear that he is not in support of a wealth tax" and argues California already depends heavily on high earners, with more than 80 billionaires from the 2025 Forbes 400 list residing in the state. The concern is structural. One-time revenue funds ongoing costs for exactly one year, and if even a fraction of California's billionaire class relocates, the state loses compounding future capital gains, income, and payroll tax revenue that would dwarf the one-time take.

Google co-founder Sergey Brin has already moved to put money on the other side of this fight, pouring tens of millions into counter-ballot measures that would effectively undermine the tax, according to the Sacramento Bee. Two of those measures have collected enough signatures to qualify but are awaiting final validation. Google co-founder Larry Page has also already left California, per Business Insider.

The Sacramento Bee and Business Insider both report these dynamics without much daylight between them. Newsweek adds the prediction market data, which is the most concrete signal of where politically-engaged observers think this ends up.

The Polymarket Signal

Polymarket placed the odds of the tax qualifying for the ballot at 31% on Tuesday, down from 90% at the start of June and 74% as recently as Sunday, according to Newsweek. Prediction markets can be wrong, and they've been wrong before on California ballot fights. A drop that steep that fast reflects traders pricing in Newsom's pressure campaign as serious, not performative.

The tax is retroactive to any California resident with assets exceeding $1 billion as of January 1, 2026. Business Insider reported earlier this year that more than 200 California residents meet that threshold.

What Happens Next

If SEIU-UHW doesn't withdraw and state officials certify the signatures by June 25, the measure goes to voters in November. Newsom cannot veto a ballot initiative. His only path to killing it is negotiation before the deadline.

No compromise terms have been made public. If Newsom offers a legislative alternative, that alternative would have to clear both chambers and survive a state budget already under pressure. Whether any deal credible enough to satisfy SEIU-UHW can be assembled in seven days is genuinely unclear.