New York’s Warning for Democratic Leaders

In the weeks after he was elected mayor of New York City last fall, Zohran Mamdani worked behind the scenes to torpedo a bid by one of his allies, a charismatic young democratic socialist, to challenge the reelection of House Minority Leader Hakeem Jeffries in Brooklyn. Such a high-profile primary fight, Mamdani reportedly argued at the time, could slow his agenda for the city.In light of what happened last night, Mamdani’s intervention might have saved the political career of a man who could become the nation’s first Black House speaker next year. Mamdani picked other primary battles across the city, and he won them all. Candidates whom the mayor backed defeated two House Democratic incumbents: Representative Dan Goldman in Manhattan and Brooklyn, and Harlem Representative Adriano Espaillat, the chair of the Congressional Hispanic Caucus. In another open-seat race, the Mamdani-endorsed state legislator Claire Valdez swamped a Democrat who had the support of much of the party’s local establishment.The insurgent victories exposed a striking dynamic with significant implications for national politics: America’s two most powerful Democrats, Jeffries and Senate Minority Leader Chuck Schumer, both hail from New York City, but they are not the dominant force in their own hometown. For the moment, that distinction belongs indisputably to Mamdani, the 34-year-old whose winning mayoral campaign last year took both men—and almost everyone else—by surprise.Mamdani first endorsed Brad Lander, a rival turned ally in last year’s mayoral race. Lander trounced Goldman, a second-term Democrat and an heir to the Levi Strauss fortune, largely by playing up their differences over Israel in a district that includes some of the city’s most progressive neighborhoods. The mayor made a much bigger bet in backing Darializa Avila Chevalier, a 32-year-old democratic socialist challenging Espaillat, a five-term incumbent whom Mamdani had initially promised to endorse. Avila Chevalier has taken