A Wealth Tax on Billionaires? California Voters to Decide Prop 40

California voters will decide on November 3 whether to approve Proposition 40, a proposed one-time 5 percent tax on the net worth of the state’s billionaires. The initiative aims to generate approximately $100 billion in revenue, with roughly 90 percent directed toward public healthcare services. Proponents argue the funds are necessary to prevent millions of Californians from losing medical coverage due to recent federal budget cuts. The measure has sparked a contentious battle involving billions of dollars in campaign spending, deep divisions within the Democratic Party, and intense national attention regarding the taxation of extreme wealth. Senator Bernie Sanders described the ballot initiative as the most important in the country. Under the proposal, individuals with a net worth exceeding $1 billion would be assessed on their assets and unrealized capital gains. Representative Ro Khanna, a Democrat representing California, stated that the tax targets roughly 250 billionaires whose collective wealth amounts to $2.1 trillion. Khanna noted that these individuals hold half of the California economy and that their wealth increased by 144 percent over the previous three years. He argued that the tax is essential to ensure that 3.5 million Californians retain healthcare access and that children do not go without care. Lorena Gonzalez, president of the California Federation of Labor Unions, emphasized that the tax serves to backfill healthcare funding lost to federal reductions. She stated that working people should not bear the cost of tax breaks given to billionaires. The opposition to Proposition 40 is well-funded and led by prominent figures in the technology sector. Google co-founder Sergey Brin has donated over $100 million to the campaign against the measure. Specifically, Brin contributed $102 million to Building a Better California, an organization supporting two alternative ballot measures designed to nullify Proposition 40 even if it receives a majority vote. Brin, who has a net worth estimated at $281 billion, has claimed to have moved out of the state, a move that could allow him to avoid the tax. Other major contributors to the opposition include former Google CEO Eric Schmidt, Palantir co-founder Peter Thiel, venture capitalist John Doerr, and DoorDash executive Tony Xu. These billionaires have also supported competing ballot initiatives intended to block the wealth tax. Campaign spending data reveals a significant financial imbalance between the two sides. Opposition efforts have assembled more than $340 million, with expenditures exceeding $1 million per day during the first half of September. Dave Regan, head of the healthcare workers' union sponsoring Proposition 40, predicted that opposition groups would spend at least $400 million by election day. In contrast, the proponents of the tax have raised $32 million, amounting to less than 10 percent of the opposition’s resources. Despite the disparity in funding, early polling suggested the measure had support. Between August and mid-September, six independent surveys indicated that California voters favored a yes vote by margins ranging from 2 to 10 percent. However, later polls suggest a shift in momentum. A survey by the Independent Voter Project in late September showed the no side leading by four points. A subsequent survey by the Manhattan Institute reported the no vote pulling ahead by a 15-point margin. The political landscape surrounding the measure is fractured. While the California Democratic Party officially endorsed Proposition 40, Governor Gavin Newsom opposes it. Representative Ro Khanna attributed Newsom’s opposition to the influence of billionaire donors who fund his political campaigns. Other notable opponents include the California Teachers Association and Planned Parenthood. Although Planned Parenthood leadership opposes the measure, some staff members have publicly announced their support for the billionaire tax. Opponents of the proposition argue that the threat of the tax is already causing an exodus of high-net-worth residents, which they claim threatens long-term damage to the state’s revenue base and broader economy. They contend that the measure represents a departure from conventional state personal taxes, which typically levy income rather than accumulated wealth. Supporters and critics disagree on fundamental aspects of the policy, including the potential revenue yield and the likelihood of wealthy residents leaving the state. Experts note that wealth tax revenue estimates face inherent limitations and that the answers to these questions are politically complex rather than purely mathematical. The debate extends beyond fiscal mechanics to broader concerns about economic disparity and the political power of ultra-wealthy individuals. Contextual data highlights the current economic climate: the 25 wealthiest Americans pay a true tax rate of just 3.4 percent, while holding about 2 percent of the nation's wealth. This concentration is comparable to the wealth held by the entire bottom half of the country. Furthermore, workers' share of economic output has fallen to 52.8 percent, the lowest level recorded since 1947. Meanwhile, billionaire wealth reached an all-time high, with Forbes counting a record 3,428 billionaires worth $20.1 trillion earlier this year. The initiative marks the first time in U.S. history that voters are considering a direct tax on billionaire wealth. Similar measures have gained traction elsewhere, with a dozen states advancing millionaire or billionaire taxes this year. Maine, Washington, Hawaii, and Rhode Island have already enacted such taxes. Senator Bernie Sanders and Representative Ro Khanna have also introduced a federal version of the proposal. The momentum for taxing the wealthy echoes trends from the Progressive Era. Critics of the wealth tax movement argue that billionaires are symptoms of deeper structural issues related to corporate power and market concentration, rather than the root cause of economic dysfunction. They point to rising corporate margins and weakened competition as primary drivers of inequality. Regardless of these theoretical debates, the outcome of the California vote will determine whether the state implements a novel mechanism for taxing extreme wealth to fund public health infrastructure.