Democratic leaders in California reached a narrow consensus this weekend to endorse a controversial ballot measure that would impose a one-time tax on the net worth of residents with assets exceeding $1 billion. The decision came after three days of intense debate during the California Democratic Party’s executive board meeting in San Diego, reflecting deep divisions within the party over how best to address economic inequality.

Known as Proposition 40, the measure would be the first of its kind in the United States, taxing individuals based on the total value of their wealth—including stocks, trusts, real estate, and valuable possessions. If passed in November, the tax is expected to generate tens of billions of dollars earmarked for health care programs, including Medicaid funding that Democratic backers say is critical amid recent cutbacks.

Despite broad Democratic support for raising taxes on the wealthy nationwide, the California proposal has divided the party’s key constituencies. Labor unions, including the Service Employees International Union-United Healthcare Workers West, which sponsored the measure, argued that Proposition 40 is a necessary step to prevent further losses in health coverage and hospital services. “They are, frankly, just out of step with the great majority of the people they claim to represent,” said Dave Regan, president of the union, criticizing opponents within the party.

However, other influential groups such as the California Teachers Association and Planned Parenthood Affiliates of California, which represent progressive interests, opposed the tax, contending it lacks sustainable funding for a broader range of public services. The associate executive director of the California Teachers Association, Teri Holloman, acknowledged the unusual stance of her union, which supports taxing billionaires in principle but considers Proposition 40 the wrong mechanism.

The ballot measure also places the California Democratic Party at odds with the state’s top elected Democrats. Governor Gavin Newsom and Xavier Becerra, the Democratic candidate aiming to succeed Newsom, have both spoken out against the billionaire tax, warning that it could drive wealthy entrepreneurs from the state and reduce long-term revenue for essential programs like education.

The debate has national implications, highlighting fault lines that run through the Democratic Party between progressive populists and more centrist voices. Representative Ro Khanna, one of the few California Democrats publicly supporting the measure, described it as “the defining fight of our party,” framing it as a choice between siding with corporate interests or economic populism.

Yet the politics behind the measure are complex. Its sponsorship by a single union that stands to benefit raises questions about the broader coalition support. Meanwhile, Republican critics have seized on the issue to portray California as hostile to business and inclined toward expanding government spending.

California is not alone in experimenting with new taxes on high earners. New York and Washington State have enacted or proposed taxes aimed at the wealthy, though California’s wealth tax proposal is unique for its scope and focus on total net worth. Billionaires in the state have already contributed over $118 million to opposing efforts aimed at nullifying the tax if it passes.

Policy experts suggest the California debate will influence Democratic economic strategies ahead of the 2028 presidential race. Some argue that wealth taxes like Proposition 40 are impractical and legally vulnerable. Jim Kessler, co-founder of a center-left think tank in Washington, D.C., advocates for alternative approaches such as raising income, capital gains, and estate taxes or closing loopholes, which he says are more feasible and effective.

As the vote approaches, Democrats nationally are watching California’s battle as a potential bellwether for the future of tax policy and the broader ideological direction of the party. For now, the endorsement by the California Democratic Party reveals a party grappling with how to balance progressive ambitions with pragmatic governance amid a growing economic divide.