SEIU-backed California billionaire tax measure qualifies for November ballot

TL;DR: SEIU-backed campaign collected over 1.5 million signatures, qualifying a proposal for a one-time 5% tax on California billionaires’ assets for the November ballot.

Context: The measure, sponsored by the Service Employees International Union-United Healthcare Workers West, needed 870,000 valid signatures to appear on the state ballot. Backers say the revenue would offset federal cuts to health services for low‑income Californians signed into law by former President Donald Trump. California has more billionaires than any other state—estimates place the number in the low hundreds—and the top 1% of earners supplies nearly half of the state’s personal income tax revenue, a key part of its nearly $350 billion budget.

Key Facts: The proposal would impose a one-time 5% levy on the total assets of individuals whose net worth exceeds one billion dollars, counting stocks, real estate, art, businesses and intellectual property. According to the campaign statement, more than 1.5 million signatures were gathered, surpassing the required threshold. The tax would apply retroactively to billionaires living in the state as of 1 January. Alphabet president Sergey Brin has contributed at least $45 million to a super PAC named Building a Better California, which aims to defeat the measure; a super PAC is a political action committee that can raise unlimited funds from donors.

What It Means: Supporters argue the tax would protect emergency rooms and hospital staffing amid reduced federal funding. Opponents, including the California Business Roundtable and several tech moguls, warn that the levy could encourage wealthy residents to move assets or residency out of state, potentially reducing future tax revenue. The measure has also widened a split within the Democratic Party, with progressive figures such as Senator Bernie Sanders endorsing it while Governor Newsom remains opposed. Analysts note that an exodus of billionaires could cost the state hundreds of millions in tax dollars, though the union characterizes that risk as exaggerated.

What to watch next: Voters will decide the fate of the tax in November, and observers will monitor potential legal challenges, any shifts in billionaire domicile, campaign spending trends, and how the outcome may influence Governor Newsom’s prospective 2028 presidential bid.