California voters face competing November 2026 ballot measures, with Proposition 42 positioned to block new taxes on personal property ownership—including financial assets, retirement accounts, and business interests—while limiting retroactive taxation based on prior residency or conduct. The measure directly counters the billionaire wealth tax initiative, and if both pass the one receiving more votes prevails, creating high-stakes interaction. Trader consensus near 51 percent against passage reflects divided interests: business, construction, and firefighter groups back the prohibition on double taxation and retroactive rules, while unions and healthcare advocates oppose it to preserve revenue options for services. Key variables include campaign spending intensity, polling shifts on wealth taxation, and any pre-election legal developments concerning retroactivity that could alter perceived viability.