California voters will decide Proposition 43 in November 2026, a legislatively referred constitutional amendment that would require a two-thirds supermajority for citizen-initiated local special taxes to pass, closing a majority-vote loophole created by prior court rulings and extending the threshold already applied to governing-body referrals. The measure emerged from a June 2026 legislative compromise with the Howard Jarvis Taxpayers Association after an earlier citizen initiative was withdrawn, passing both chambers with broad bipartisan margins. Opposition from transit, education, and local-service advocates highlights risks to revenue for housing, infrastructure, and public programs, while supporters emphasize restoring Prop 13-era taxpayer protections. Early surveys on related local-tax limits show partisan splits and sub-50% support among likely voters, contributing to trader consensus reflected in the 62% implied probability against passage. Key upcoming factors include campaign spending by taxpayer groups versus public-sector unions and any fall polling shifts before election day.