California’s Proposition 40 has become a major political and financial fight, drawing millions of dollars from Silicon Valley donors including Sergey Brin, Chris Larsen, John Doerr and Peter Thiel. The measure would impose a one-time 5% tax on certain California residents with wealth above $1 billion and supporters say it could raise about $100 billion over five years, primarily for health care, food assistance and education. Steve Hilton called the proposal an unconstitutional "asset-seizure tax" and warned it could drive founders, investors and top talent out of Silicon Valley; he claimed about $1 trillion in wealth had already left California and cost the state billions in potential revenue. Mark Cuban raised similar concerns about founders who are rich in shares but short on cash, while Rep. Ro Khanna and other supporters argue deferral options could address liquidity concerns. A Berkeley IGS poll showed likely voters supporting Proposition 40 by 48% to 41%, with 11% undecided, even as prediction-market pricing declined.