San Francisco Democrats voted 17-4 to oppose Proposition 40, California’s proposed one-time 5% tax on the net worth of people who were state residents on January 1, 2026, and held more than $1 billion in assets. Five members abstained, five were absent and one did not endorse the measure; Nancy Pelosi also declined to endorse it. The vote came weeks after the California Democratic Party backed Proposition 40 in August with more than 60% support. Californians will vote on the measure in November. It would affect about 200 billionaires holding more than $2 trillion in combined assets and could deliver up to $100 billion to a 2026 Billionaire Tax Reserve Fund. Ninety percent of the proceeds would support healthcare, with the remainder directed to education and food assistance. Supporters cite the One Big Beautiful Bill Act of 2025, which provided tax cuts for wealthy Americans and initiated federal Medicaid reductions expected to exceed $1 trillion over the next decade. The Legislative Analyst’s Office estimates tens of billions of dollars in temporary revenue over several years, while warning that billionaire behavior, stock-price changes and possible departures make collections difficult to predict. Six billionaires have already ended their California residency ahead of the January 1 deadline. Billionaire-backed Propositions 41 and 42 would constrain or eliminate Proposition 40, while Governor Gavin Newsom and gubernatorial candidate Xavier Becerra oppose it. A University of California, Berkeley poll found 48% of potential voters supported Proposition 40 and 41% opposed it.