California voters will decide Proposition 43 on November 3, 2026, a legislatively referred constitutional amendment that would require two-thirds approval for new, extended, or increased local special taxes placed on the ballot by citizen initiative, closing a post-2017 loophole while applying only prospectively from January 1, 2027. The measure emerged from a June 2026 compromise between Democratic legislative leaders, Governor Newsom, and the Howard Jarvis Taxpayers Association, which withdrew a broader, retroactive initiative that also targeted real estate transfer taxes like Los Angeles’ Measure ULA. Local governments, unions, and revenue advocates oppose the change, arguing it would constrain funding for services; anti-tax groups support restoring the higher threshold historically applied to government-referred measures. Trader sentiment favoring rejection at 57% reflects the narrowed scope, organized opposition from fiscal stakeholders, and historical difficulty passing tax-related restrictions without broader retroactive elements.