**Proposition 43 on California’s November 3, 2026 ballot would amend the state constitution to require a two-thirds voter approval for citizen-initiated local special taxes, aligning them with the existing threshold for legislatively referred measures and prohibiting certain charter-city real estate transfer taxes.** Traders assign a 64.5% probability to rejection, reflecting limited early momentum for the measure despite its legislative referral and strong bipartisan passage in the Assembly and Senate in June 2026 as part of a compromise that removed a competing initiative. Opposition campaigns, backed by groups focused on local services such as fire protection, transit, and healthcare, argue the change would empower a minority of voters to block revenue measures and constrain funding options. Supporters, including taxpayer organizations, frame it as restoring constitutional protections originally tied to Proposition 13. With roughly $1.4 million raised for the “yes” side and $500,000 for “no” as of recent filings, and no public polls showing decisive support, the current odds align with historical patterns in which measures tightening tax rules face headwinds in a state where many recent local tax initiatives have passed with simple majorities. Key upcoming factors include fall campaign spending, endorsements, and voter turnout dynamics in a midterm environment crowded with other propositions on taxes, housing, and healthcare.