California Proposition 43 would close the Upland loophole by requiring two-thirds voter approval for citizen-initiated local special taxes starting in 2027, aligning them with the threshold already applied to government-proposed measures while leaving general taxes and existing rules largely intact. The measure emerged from a June 2026 legislative compromise that withdrew a more restrictive Howard Jarvis-backed initiative, removing retroactive invalidations and transfer-tax limits to broaden support. Trader sentiment remains closely balanced near even odds because the change pits long-standing taxpayer protections rooted in Proposition 13 against local governments’ reliance on majority-approved initiatives to fund schools, infrastructure, and services. Upcoming campaign spending, endorsements from municipal groups or business organizations, and any polling on fiscal priorities could shift probabilities in either direction before the November 3, 2026 vote.