Washington voters will decide Initiative 645 on November 3, 2026, which would repeal the 9.9% tax on household income above $1 million enacted by Senate Bill 6346 and signed by Governor Bob Ferguson in March. The measure qualified for the ballot after supporters gathered more than 500,000 signatures, but traders assign only a 23.5% chance of passage. Key factors include the state-required ballot disclosure stating repeal would reduce funding for K-12 education, higher education, and human services, which polling has linked to lower support for similar tax-cut initiatives. Opposition from the governor, organized labor, and Democratic legislative majorities emphasizes revenue for public services, while historical voter rejection of capital gains tax repeal efforts in 2024 informs assessments of the repeal’s prospects. Ongoing litigation over the tax’s constitutionality and the initiative’s potential effects on related revenue measures adds uncertainty ahead of the vote.