By RuthThe Money Desk
California's final filing on Proposition 40 closed at $425 million spent to defeat it, the most expensive opposition campaign in state history, outspending the measure's own backers 250 to 1. The tax itself asked billionaires for a nickel on the dollar, once, on wealth over $1 billion, to backfill the hole the Big Beautiful Bill tore in the state's Medicaid budget.
The opposition did not wait for November. On August 25th, groups funded by Google co-founder Sergey Brin and venture capitalist Peter Thiel opened an advertising campaign against the measure under two names: Building a Better California, and Californians Against Wasteful Spending and Higher Taxes. Read against the filing that followed, the second name describes the opposition's own ledger better than it describes the tax.
By October 27th, Senator Bernie Sanders put a number to the fight in progress: $333 million already committed to beating Proposition 40. Sanders asked, on the record, what else that sum could buy. Not homelessness, he said. Not cancer. Not child poverty. A 5 percent tax on billionaires is what the money was spent to stop.
On November 1st, the Hill reported the measure dividing California's own Democrats, with experts quoted calling the tax's broader economic impact "nuanced." Nine days remained before the vote.
On November 10th, Proposition 40 failed. The final filing landed at $425 million, the figure the state now carries as its costliest opposition campaign on record. Online that night, the toasts ran to one name. Y Combinator's chief executive, Garry Tan, wrote: "Huge thanks to Sergey Brin here." Venture capitalist Ilya Sukhar posted: "God bless Sergey Brin." Crypto entrepreneur David Marcus posted one word: "Hero."
That settles the one-time question. It does not settle the standing one. No date for that vote is in the filing yet.
The nickel-on-the-dollar ask is closed, hon. The Medicaid hole it was written to backfill is not. Somebody still pays for that hole. The filing says only who already spent $425 million to make sure it isn't them.