Supporters of California's proposed billionaire tax are taking their fight against Gov. Gavin Newsom into five other states, planning a six-figure advertising campaign that challenges his opposition as he considers a possible 2028 presidential bid.
The television and digital advertisements are expected to reach South Carolina, Nevada, New Mexico, Virginia and New Hampshire, according to campaign organisers. Those audiences cannot vote on California's Proposition 40, but the campaign could introduce the dispute to voters who may help choose the next Democratic presidential nominee.
"Gavin Newsom turned his back on working Californians. Will he do the same to you?" a narrator asks in a 30-second advertisement obtained by the Los Angeles Times.
The advertisement connects Newsom's opposition to wealthy supporters, naming crypto executive Chris Larsen, businessman Stewart Resnick, former Google leader Eric Schmidt and venture capitalist Michael Moritz. Its suggestion that donors determined his position is the campaign's argument, rather than an established finding.
Proposition 40, on California's November 3 ballot, would impose a one-time 5% tax on qualifying billionaires who were state residents on January 1, 2026. Real estate, pensions and retirement accounts would generally be excluded.
California's official voter guide says 90% of proceeds would support healthcare, with the remainder allocated to education, food assistance and tax administration. Supporters say the funding would help offset federal Medicaid cuts.
The advertising purchase, which backers say could expand, is principally funded by healthcare union SEIU-UHW West, progressive organiser Saikat Chakrabarti and early Stripe engineer Ross Boucher. The union helped put the proposal before voters.
Newsom supports a national minimum tax on billionaires but argues that California acting alone could encourage wealthy residents to relocate, eroding a revenue base on which the state depends. In June, he described the American tax system as "fundamentally broken".
He also objects to allocating nearly all the proceeds to healthcare when schools, housing, childcare and public safety need funding.
The state's nonpartisan legislative analyst estimates the measure could generate tens of billions of dollars over several years, while potentially reducing annual state income-tax revenue by less than $1 billion.
The dispute has divided Democratic allies. Sen. Bernie Sanders and the California Democratic Party support Proposition 40, while the California Teachers Association opposes it alongside Newsom.
According to Politico, Newsom personally urged the measure's backers to withdraw it, but has not been fundraising or leading its opposition messaging.
Opponents nonetheless hold a substantial financial advantage. California election records show their committees reported $130.3 million in contributions through October 22, compared with $33.4 million for supporters.
Larsen, who has said he intends to support Newsom in 2028, contributed more than $12 million to opposing Proposition 40, KQED reported. Those donations went toward defeating the measure, not to Newsom's campaign.
The governor has not announced a presidential run. His recent travel, however, has included New Hampshire, South Carolina and Nevada, according to the Los Angeles Times.
A September UC Berkeley IGS poll found 45% of likely California voters supported Proposition 40 and 42% opposed it, CNBC reported. Even if approved, the tax could be blocked by competing Propositions 41 and 42, depending on their vote totals and a court's determination of whether the measures conflict, the official voter guide says.
