California voters face a landmark billionaire wealth tax on the ballot

On November 3, Californians will decide on Proposition 40, a ballot initiative that would impose a one-time wealth tax on a limited number of billionaires, largely aimed at Silicon Valley executives. The proposal is expected to raise a large sum for the state, prompting a fiercely contested campaign funded by both labor unions and billionaire opponents who have created organizations like Build a Better California and Golden State Promise.

Dave Regan, president of the SEIU-United Healthcare Workers West, leads the pro-tax effort, while figures such as Sergey Brin, Marc Andreessen and Michael Moritz have mobilized resources to block it. Political backing is fragmented: Governor Gavin Newsom and most Democratic officeholders oppose the measure, whereas a handful of legislators and activist groups support it. The vote could set a precedent for wealth taxes in the United States and influence the 2028 presidential race, especially as tech wealth continues to grow.