California voters have overwhelmingly rejected Proposition 40, defeating a proposed one-time 5% tax on the net worth of billionaires following a massive spending campaign by opponents. News outlets including the Associated Press, NBC News, and CBS News projected the failure of the controversial ballot initiative on Monday after voters expressed strong opposition to the levy.
The measure targeted California's ultra-wealthy residents in a high-stakes legislative experiment that attracted national political attention. However, voters ultimately sided with critics who argued that squeezing the state's richest individuals could inflict broader harm on the local economy.
How much money was spent to defeat Proposition 40?
Opponents of Proposition 40 spent $378 million to defeat the billionaire wealth tax measure, according to reporting from CalMatters. Tech leaders and corporate executives led the opposition effort, outspending proponents of the initiative by approximately 10 to 1, TechCrunch reported.
The massive political expenditure handed a major victory to tech leaders and high-net-worth founders who argued the tax would disrupt the business ecosystem. The funding disparity allowed opponents to run aggressive campaigns warning voters about potential negative spillovers into the broader state economy.

Opponents of Proposition 40 outspent backers roughly 10 to 1, pouring $378 million into the effort to defeat the proposed billionaire tax.
Why did voters reject the California billionaire tax?
Voters rejected the California billionaire tax due to growing concerns that taxing ultra-wealthy residents would encourage capital flight and ultimately damage the state's economic standing, according to the Los Angeles Times. Economic experts and tech leaders raised public alarms that a 5% net worth levy would force high earners and businesses to relocate out of state.
The defeat of Proposition 40 also highlights deep political fractures within the Democratic Party over tax policy and fiscal governance, NPR reported. While progressive factions championed the initiative to generate substantial revenue from the state's wealthy elite, moderate Democrats and corporate interests warned of severe economic blowback.
What would Proposition 40 have done if passed?
Proposition 40 would have imposed a one-time 5% tax directly on the total net worth of billionaires residing in California, according to reporting from France 24 and TechCrunch. Unlike traditional income taxes, the proposal aimed to capture global accumulated asset wealth above the billion-dollar threshold.

The proposal was framed by progressive advocates as a historical blow to economic inequality, aimed at ensuring the state's richest residents contributed more toward public services. However, the defeat of Proposition 40 marks a significant political setback for progressive organizers attempting to enact wealth taxes across the United States.