New York City Mayor Zohran Mamdani scored a sweeping political victory on Tuesday as all three of his endorsed candidates won their Democratic congressional primaries, defeating two sitting members of Congress and reshaping the left flank of the party in America's largest city. The results delivered a sharp rebuke to the Democratic establishment and signalled growing momentum for the democratic socialist movement within the party.

Former New York City Comptroller Brad Lander defeated two-term incumbent Dan Goldman in the 10th Congressional District, covering Lower Manhattan and parts of Brooklyn, by a wide margin of roughly 66% to 34%. In upper Manhattan and the Bronx, activist and doctoral student Darializa Avila Chevalier — at 32, a first-time candidate — narrowly unseated Adriano Espaillat, a five-term congressman who chairs the Congressional Hispanic Caucus and was the first Dominican American elected to Congress. Meanwhile, state Assembly Member Claire Valdez won the open seat being vacated by retiring Representative Nydia Velazquez, defeating Brooklyn Borough President Antonio Reynoso in a district spanning parts of Brooklyn and Queens. All three candidates identify with or have aligned themselves with democratic socialist politics, and all ran on platforms calling to abolish the federal immigration enforcement agency ICE, describing Israel's military campaign in Gaza as genocide, and promising to tax the wealthy.

The war in Gaza was a defining fault line. The race between Lander and Goldman — both Jewish — crystallised the tension: Goldman had consistently criticised Israel's government and condemned settler violence but declined to use the word genocide, while Lander made that charge central to his campaign. AIPAC, the influential pro-Israel lobbying group that poured more than $126 million into electoral races last cycle, had backed several of the establishment candidates. Mamdani himself described AIPAC in a campaign speech as a