California's landmark billionaire wealth tax proposal has qualified for the ballot despite fierce opposition from the ultra-wealthy, major Democrats, and unions—revealing deep divisions even among those who support taxing the rich. Laurel Rosenhall explains how a labor union leader's maverick initiative could reshape wealth taxation nationwide, but also why the measure's unusual structure and origins have made unlikely allies of its opponents. A 5% tax on billionaire assets in California would affect roughly 200 people and dedicate 90% of revenue to healthcare, marking an unprecedented shift from taxing income to taxing wealth itself.