Supporters of a proposed one‑time 5 percent tax on California billionaires say they have gathered over 1.5 million signatures, enough to force a ballot test in November. The Service Employees International Union‑United Healthcare Workers West, backed by Gov. Gavin Newsom and Senator Bernie Sanders, aims to raise funds to replace $20 billion in lost Medicaid funding.

Opponents, including tech magnates Ron Conway and Sergey Brin, argue the tax would cripple California’s startup ecosystem, citing a study that projects a loss of 108,000 high‑paying jobs and billions in income tax revenue over two decades. The Legislative Analyst’s Office warned that the measure could reduce state income tax receipts by hundreds of millions annually if billionaires flee.

If the measure clears verification, proponents have until late June to decide whether to place it on the ballot; competitors may also qualify, potentially forcing a split vote. The election battle will test California’s willingness to tax the ultra‑wealthy while balancing the state’s reputation as a tech hub. Business leaders warn that a passed tax could prompt billionaires to relocate, draining talent and startup capital.