California voters decide Proposition 40 on November 3, 2026, a 5% one-time tax on the wealth of the state's roughly 250 billionaires to fund healthcare, projected to raise around $100 billion. Opponents have raised $333 million, mostly from Sergey Brin, and Planned Parenthood and the California Teachers Association also oppose it. A late September poll put support at 45% to 42%. The residency question is contested: one account says seven billionaires holding $540 billion left before the January 1 snapshot, while economist Gabriel Zucman says none did. Hoover scholars estimate a $40 billion shortfall; Zucman says three million would lose Medicaid if it fails.