California voters rejected Proposition 40, the proposed one-time 5 percent tax on billionaires, according to the Associated Press. The measure went down to defeat after a costly campaign that pitted tech industry money against its backers. The result marks a significant win for the wealthy individuals the tax would have targeted.

Tech leaders outspent supporters of the measure by roughly ten to one, according to reports. The lopsided spending advantage helped fuel a campaign that ultimately persuaded voters to turn down the proposal. The defeat represents a major setback for advocates who argued the tax would help address inequality in the state.

The proposition would have imposed a one-time 5 percent levy on the state's billionaires, a group that includes many prominent technology founders and executives. Supporters framed it as a way to generate revenue from those most able to pay, while opponents argued it would drive wealth and business out of California.

The outcome underscores the political influence of the tech industry in California and its ability to mobilize resources against measures it opposes. The defeat also raises questions about the viability of similar wealth tax proposals in other states and at the national level.

The campaign unfolded against a backdrop of growing debate over wealth concentration in California, home to some of the world's largest technology companies and the fortunes they have created. Backers of the measure had argued that a one-time levy on the state's billionaires represented a modest ask of those whose wealth has soared in recent years, and that the revenue could have addressed pressing needs across the state. Opponents countered that the tax would encourage the state's wealthiest residents to relocate, taking their tax dollars and businesses with them.

The roughly ten-to-one spending gap proved decisive in shaping the public debate, allowing opponents to dominate advertising and messaging in the final stretch of the campaign. For the tech leaders who financed the opposition effort, the result affirmed their capacity to defeat measures they view as hostile to their interests. For the proposal's advocates, the loss leaves them searching for a path forward on wealth taxation in a state where the industry's political footprint remains formidable.