California's billionaire class includes Dr. Dre, Tim Cook, Marissa Mayer, Mark Zuckerberg, Beyoncé, and Jay Z, among hundreds of others. Illustration by Claudine Hellmuth/POLITICO (Getty)

California's 2026 election has been the year of the billionaire.

For months, a small handful of very, very wealthy people deployed their vast resources in unprecedented sums up and down the ballot. And while their spending drew widespread attention, a new analysis by POLITICO — which, like Business Insider, is part of the Axel Springer Global Reporters Network — offers a more revealing look at their party affiliations and voting habits.

Some have made their politics abundantly clear.

Tom Steyer, the billionaire philanthropist, attempted this year to buy his way to the governor's mansion with an ultimately unsuccessful $200-plus million primary campaign.

SEIU-UHW's pursuit of Proposition 40 , a one-time tax on the state's wealthiest residents, put billionaires on the ballot explicitly, prompting a more than $300 million…