Russell Berman: “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 i…