NYC's democratic socialist mayor is racking up early wins, good news for his voters and a headache for moderate Democrats trying to distance themselves from him.

• Mamdani froze rent for 2 million rent-stabilized apartments for two years, a key campaign promise delivered.
• His other early moves include free preschool for 2-year-olds, money clawed back from bad landlords, filled potholes, and record-low crime.
• His favorability is climbing — about 58% favorable in New York City, up since spring.
• Moderate Democrats like Josh Gottheimer and Josh Shapiro are pushing back, releasing a "capitalist not socialist" manifesto, but DSA-backed candidates keep winning primaries in New York, Pennsylvania, and Michigan.
• His pragmatic, show-don't-tell style and communal events are broadening the left's coalition beyond young white activists to Black and Hispanic voters.

Outlook: Mamdani's wins are making democratic socialism harder for centrist Democrats to dismiss heading into the fall, though critics warn rent freezes could backfire on housing quality over time.