California billionaire tax heads to ballot as Newsom fights measure

California’s billionaire tax is headed toward the November ballot with a 5% one-time levy on residents whose net worth tops $1 billion, unless Gov. Gavin Newsom and other opponents strike a last-minute deal to pull it down. Backers say the 2026 Billionaire Tax Act would hit about 200 Californians and could raise roughly $100 billion over five years, money they want steered to Medi-Cal, public education and food assistance.

The campaign has already cleared a major hurdle. California Secretary of State Shirley Weber said the measure was cleared to begin collecting signatures on Dec. 26, 2025, and supporters said they submitted 1.55 million signatures on April 27, 2026, far above the roughly 875,000 valid signatures needed to qualify. That would put Initiative No. 25-0024 before voters in November 2026, setting up one of the most expensive ballot fights in California history.

The push is framed as a response to the state’s fiscal and health care squeeze. The measure’s backers say California’s safety net faces extraordinary pressure from projected Medi-Cal cuts of up to $19 billion a year, or about $190 billion over 10 years, and argue the tax is needed to prevent hospital and clinic closures as federal support tightens. Opponents say the proposal would punish investment, weaken the state’s business climate and accelerate the flight of wealthy residents out of California.

Newsom has emerged as the most prominent Democratic opponent. He has warned that the tax could damage California’s economy and push billionaires to leave, and in June he and allied groups were still trying to block or negotiate the measure before a late-June deadline. That scramble underscores how difficult wealth-tax proposals have been to translate from political slogan to enacted policy, even in a state where Democrats dominate statewide politics.

The fight has also split labor and other Democratic-aligned groups. Bernie Sanders has backed the measure, while unions representing construction workers, carpenters, police officers and teachers, along with organizations such as Planned Parenthood, broke with SEIU-UHW to oppose it. Wealthy Californians and Silicon Valley figures have lined up against the proposal as well, arguing it would drive more billionaires out of the state.

Early polling showed how unsettled the race was. A January 2026 survey found 48% support and 38% opposition before voters were given more information; after positive and negative arguments were read, support slipped to 46% and opposition rose to 44%. With both sides already spending heavily, the contest is shaping up as a real-world test of whether even deep-blue California can tax extreme wealth without triggering the legal, political and economic backlash that has stalled similar efforts elsewhere.