California billionaire tax heads to November ballot after union defies Newsom and tech moguls

The ballot measure

The California Billionaire Tax Act would impose a one-time 5% levy on the net worth of any state resident exceeding $1 billion as of January 1, 2026. Backed by the Service Employees International Union-United Healthcare Workers West (SEIU-UHW), the proposal aims to raise roughly $100 billion, primarily to shore up Medicaid and other health, education and food-assistance programs after federal cuts enacted under President Trump's One Big Beautiful Bill Act.

“Regular working people pay higher effective tax rates than the wealthiest Americans.”

Deadline drama

The union had until 5 p.m. on Thursday to pull the measure from the ballot. Negotiations with Governor Gavin Newsom, who opposes the tax, failed to produce a deal, and the secretary of state certified the initiative later that evening. The campaign gathered more than 1.55 million signatures by April, over twice the threshold required.

“We understand how powerful and how wealthy and how formidable the billionaires are, but this was not a hard decision for the members of our union.”

“We aren't backing down.”

Opposition from Newsom and billionaires

Governor Newsom, a moderate Democrat weighing a 2028 presidential run, argues the tax is a temporary fix that would drive wealthy residents out of California, eroding the income-tax base. A coalition of healthcare, education and housing groups, including the California Medical Association and California School Boards Association, also opposes the measure, calling it a threat to stable funding.

“Driving away the state's sustainable tax base for a one-time grab is bad policy and an even worse deal for 40 million Californians who will be left holding the bag.”

Tech billionaires have poured millions into opposition efforts. Palantir co-founder Peter Thiel, crypto billionaire Chris Larsen, and Google co-founders Sergey Brin and Larry Page are among the financiers. Brin alone has spent tens of millions since January. Opponents have also qualified competing ballot measures designed to undercut the tax.

National implications

The fight has become a proxy for the broader Democratic debate over wealth inequality. Vermont Senator Bernie Sanders has championed the measure as a model for federal action, while progressive mayors like New York City's Zohran Mamdani and Los Angeles candidate Nithya Raman have tied their campaigns to similar themes.

“Never before have so few people had so much wealth and so much power.”

What's next

The nonpartisan Legislative Analyst's Office estimates the tax would generate tens of billions in its first few years, but that income-tax revenues would subsequently decline by hundreds of millions of dollars annually. Campaign spending is expected to shatter records as both sides mobilize for November.