A proposed California ballot measure that would impose a one-time 5% tax on the state’s approximately 200 billionaires to fund healthcare has revealed deep divisions among progressive labor unions and Democratic leaders. Known as Proposition 40, the initiative seeks to raise an estimated $100 billion to offset Medicaid funding cuts enacted last year under former President Trump. The measure is chiefly supported by the Service Employees International Union-United Healthcare Workers West (SEIU-UHW), led by President Dave Regan, who designed the proposal to address what he describes as "the imminent collapse of California’s healthcare system."

Despite initial momentum, Proposition 40 has encountered opposition not only from wealthy Californians targeted by the tax but also from some influential labor unions and establishment Democrats whose backing is considered critical for the measure’s success. The California Teachers Association and the State Building and Construction Trades Council of California have publicly opposed the tax, arguing it would not provide sustainable funding for schools and communities. However, other unions, such as Teamsters California and AFSCME California, have expressed support. Some prominent labor organizations, including the California Federation of Labor Unions and SEIU California, have yet to take official positions.

Governor Gavin Newsom has been a vocal opponent since the proposal emerged, seeking to negotiate its removal from the ballot. Regan made a late offer to reduce the tax to 2% over two years, which Newsom promptly rejected. Observers suggest this move may have been an attempt to find common ground, but the initiative remains a contentious issue expected to spark an expensive and fierce campaign.

Polling indicates a narrow lead for the tax, with 52% of registered voters supporting it in a March survey by UC Berkeley’s Institute of Governmental Studies, while 33% opposed and 15% remained undecided. Nonetheless, the ballot measure’s prospects appear uncertain due in part to well-funded opposition. Several billionaires, including Google co-founder Sergey Brin, have collectively contributed over $118 million to support countermeasures designed to weaken Proposition 40’s impact.

Opposition extends beyond billionaires and includes health and education advocacy groups. Planned Parenthood Affiliates of California and the California Medical Association have joined critics, warning the measure could make state revenues more volatile and jeopardize existing funding streams for education, healthcare, public safety, and infrastructure. They contend the tax's singular focus on healthcare funding neglects broader community needs.

Supporters argue that without the tax, the state's healthcare system will suffer severe cuts, resulting in millions losing insurance coverage, thousands of healthcare worker layoffs, and increased costs for consumers. Regan emphasizes that Trump-era legislation will drain between $20 billion and $25 billion annually from California’s healthcare budget, disproportionately impacting vulnerable populations.

While some progressive figures, such as Senator Bernie Sanders and Representative Ro Khanna, have expressed support, others question whether the tax’s limited scope—which primarily benefits healthcare workers—justifies its divisiveness. Critics highlight the lack of funding dedicated to education and food security, with some unions prioritizing alternative measures like Proposition 3, which aims to create permanent taxes on high earners to fund schools and colleges.

Regan’s strategy of leveraging ballot initiatives to influence policy and negotiations is well-known and has yielded mixed results. His prior efforts secured a statewide wage floor for healthcare workers and pushed regulations on kidney dialysis clinics, although several measures he supported failed at the polls amid costly opposition campaigns.

The tax would apply retroactively to billionaires who were residents as of January 1, sparking concerns from opponents that it could drive wealthy individuals out of California, thereby reducing income tax revenues essential to the state budget. The Legislative Analyst’s Office cautioned that passage of Proposition 40 could lead to "an ongoing decrease in state income tax revenues of hundreds of millions of dollars or more per year."

As the November election approaches, Proposition 40 remains a focal point of debate over wealth taxation, healthcare funding, and the future of progressive policy alliances in California.