The race is close, and the outcome is unsettled. A Citrin Center/Politico poll released October 19 found 46% backing the tax and 43% opposed. An NBC Bay Area/Telemundo poll found 48% in favor, 38% opposed, and 14% undecided. Prediction markets, however, put the chances of passage below 30%. Economists are also disputing the revenue projections. Two Stanford economists warn the tax could leave the state $39 billion worse off in today's dollars. The Democratic split is also unresolved. Newsom and gubernatorial candidate Xavier Becerra argue the tax would drive wealthy investors and tech leaders out of California. Rep. Ro Khanna has pushed back, saying billionaires will stay and find ways to pay. Some labor leaders and their legislative allies are privately opposed, according to reporting.
For attorneys, the measure's amendment clause deserves close reading. Prop. 40 would let the Legislature amend the tax by a two-thirds vote "if the statute is consistent with and furthers the purposes of the 2026 Billionaire Tax Act." Opponents argue that language could open the door to broader taxes later, so the fight over the measure is also a fight over the Democratic Party's direction heading into 2028. Election day is November 3, and Prop. 40 is drawing more attention than the midterm races on the same ballot. Watch the final polling, the spending totals, and how the countermeasures interact with Prop. 40 if voters approve more than one.