California voters are set to decide on Proposition 40, a proposed one-time 5% tax on the wealth of the state’s approximately 250 billionaires, a measure aimed at addressing rising wealth inequality and funding healthcare. The billionaires targeted by the measure hold assets equal to nearly half of California’s economy, with their wealth increasing by 20% in the past year alone. Supporters estimate the tax could generate roughly $100 billion, of which about 90% would be allocated to preserving healthcare coverage for nearly 3 million Californians, countering federal cuts to Medicaid under the Trump administration.

The proposal has sparked a significant political divide within California’s Democratic Party and drawn clear lines between those supporting the tax and influential figures opposing it. Congressman Rohit Khanna, together with Senator Bernie Sanders, has thrown their support behind Proposition 40, framing it as a choice between aligning with working-class citizens or with wealthy corporate interests. In contrast, California Governor Gavin Newsom opposes the measure and has endorsed Proposition 42, a related ballot initiative that would permanently prohibit the state from taxing the wealth of billionaires.

Prominent tech billionaires such as Peter Thiel, Sergey Brin, and Elon Musk, all substantial donors to the Republican Party and supporters of former President Donald Trump, have been vocal opponents of Proposition 40. Thiel contributed $1.25 million to Trump's 2016 campaign, Brin nearly $500,000 to the Republican National Committee last year, and Musk spent approximately $290 million to back Trump’s political efforts. Following an October ceremony where Trump awarded Brin and Musk the National Medal of Science, Brin and Thiel have invested tens of millions of dollars to defeat Proposition 40. Musk has publicly criticized the measure on social media, warning it could lead to broader wealth taxes.

Khanna criticized Newsom for opposing the measure despite its potential to offset Medicaid funding shortfalls and improve healthcare access. According to Khanna, the governor not only resisted placing the tax initiative on the ballot but also refused to support a reduced 2% tax proposal. Newsom’s alignment with Proposition 42 has drawn accusations that he is siding with wealthy donors over public interests.

In tandem with the California debate, Khanna and Sanders introduced the Make Billionaires Pay Their Fair Share Act at the federal level earlier this year. This proposal would impose an annual 5% tax on the net worth of America’s 938 billionaires, raising more than $4 trillion over a decade. The funds would be used to restore federal healthcare cuts, provide direct payments to families, and fund free child care and college education.

Proponents of Proposition 40 argue it would establish California as the first state to implement a tax on billionaire wealth, setting a precedent for addressing systemic disparities in the taxation of accumulated assets. Critics warn that such measures could discourage investment and economic growth. As voters approach the November election, the debate over how to tax wealth and fund public services reflects broader national discussions about economic justice and the role of government in mitigating inequality.