In Michigan, there’s an effort to establish a November referendum adding an extra 5% tax on married couples with at least $1 million in taxable income, or $500,000 for individuals. The money would go to the state’s school system.In New York City, newly inaugrated Mayor Zohran Mamdani, a democratic socialist, has reiterated his call for higher income taxes on the city’s wealthy, in order to provide universal childcare. But he’ll need the support of state lawmakers to make his tax hike a reality.California is ...