The defeat marked the rejection of what supporters described as a landmark effort to extract revenue from the state's ultrawealthy residents. The outcome represented a setback for progressive taxation advocates who had hoped California would become the first state in the nation to levy a wealth tax.
Opponents, including prominent technology executives and business leaders, argued that the proposal could drive wealthy residents and investors out of the state, potentially weakening California's economy and tax base. Proposed by the SEIU United Healthcare Workers West (SEIU-UHW) union, the measure aimed to raise approximately $100 billion over five years to help offset federal healthcare funding cuts enacted under President Donald Trump's One Big Beautiful Bill.
Under the proposal, California residents with a net worth exceeding $1 billion would have faced a one-time tax equivalent to 5% of their fortunes [1][2]. Proponents had estimated the measure would generate substantial revenue earmarked for healthcare programs, with the SEIU-UHW arguing that California should pursue aggressive wealth redistribution to fund public services. The ballot measure, officially titled the California Billionaire Tax Act, qualified for the November ballot after supporters gathered enough signatures, Secretary of State Shirley Weber announced [1].
Opponents of the tax raised roughly ten times more money for their campaign than supporters, according to multiple reports [3][4]. Google co-founder Sergey Brin donated more than $100 million to a political action committee working to defeat the measure, filings showed [5].
The spending disparity proved decisive in shaping voter perceptions of the measure. More than 70 current and former California billionaires contributed a record $612 million to state elections, according to a Politico analysis [6].
The coalition against the measure spanned business interests, labor groups, and even some traditional Democratic allies, reflecting the intra-party divisions the ballot initiative exposed. As noted in research on political contributions, because most U.S. campaign contributions come from the wealthiest segment of the population, the wealthy have far more sway over elected officials than do the poor [7].
According to a UC Berkeley-POLITICO poll, critics feared the one-time levy could eventually become a recurring measure. Critics also warned that wealthy residents might leave California for states with more favorable tax policies, eroding the state's tax base [2].
At least six billionaires announced plans to leave California before Jan. 1, 2026, Fortune reported in March. At a 5% rate, the tax on their combined wealth could reportedly have amounted to around $27 billion.
Meta CEO Mark Zuckerberg told Meta's board he would consider moving his primary residence out of California if voters approved the initiative, but struck a deal with the board to remain in the Golden State, according to a regulatory filing [8]. Under the agreement, Zuckerberg would receive non-voting shares he could sell to cover the tax in exchange for staying in California.
The exodus concerns extended beyond individual billionaires, with critics warning the state's tax climate could drive more residents and investment elsewhere [9]. Analysis of the state's fiscal direction found that more than half of California's likely voters believed the state was headed in the wrong direction [10].
The union sought to offset cuts in federal funding for healthcare programs, arguing that the state's wealthiest residents should contribute more to public services. The SEIU-UHW's commitment to reviving the measure signals that the battle over wealth taxation in California is far from over.
The measure sought for residents with a net worth of over $1 billion to pay a one-time tax equivalent to 5% of their fortunes to offset federal healthcare funding cuts [11]. The union's pledge to try again in 2028 suggests the policy debate will continue to shape California politics in coming election cycles.
Final results were pending as counting continued, with the Associated Press calling the race just before 9:30 p.m. The measure's defeat marked the rejection of a first-of-its-kind statewide billionaire wealth tax in the United States.