Every congressional candidate endorsed by New York Mayor Zohran Mamdani won their Democratic primary on June 23, a clean sweep that unseated two sitting members of Congress and marked a striking expansion of the democratic-socialist movement’s reach from City Hall into Washington.
In New York’s 10th District, former city comptroller Brad Lander captured roughly two-thirds of the vote to defeat two-term Representative Dan Goldman, a prominent moderate who had been one of the chamber’s most visible Trump critics. The scale of Lander’s margin in a high-profile Manhattan and Brooklyn seat made it the night’s signature result.
In the open 7th District, where longtime Representative Nydia Velázquez is retiring, state legislator and Democratic Socialists of America member Claire Valdez defeated Brooklyn Borough President Antonio Reynoso. And in the 13th District spanning Upper Manhattan and part of the Bronx, Darializa Avila Chevalier, a 32-year-old community organizer and DSA member, narrowly ousted five-term incumbent Adriano Espaillat, 71 — an upset over an entrenched figure in Dominican-American politics.
The wins are a direct dividend of Mamdani’s own ascent. The mayor, himself a democratic socialist who pulled off an upset victory in 2025, threw his endorsement and organizing muscle behind the slate, betting that the coalition that elected him could be replicated in congressional races. The results suggest that bet paid off across very different districts.
For the national Democratic Party, the sweep lands in the middle of an unresolved argument about direction. Establishment figures have warned that a leftward tilt risks alienating swing voters, while the party’s progressive wing argues that an unapologetic economic-populist message is what mobilizes the base. Tuesday’s outcome hands the left its strongest evidence yet, defeating not just open-seat rivals but sitting members of Congress.
New York’s primaries have repeatedly served as a bellwether for intraparty energy, and the city’s electorate — younger, more diverse and increasingly receptive to DSA-aligned candidates — has become the movement’s most productive proving ground. The defeated incumbents were not fringe figures but well-funded, nationally known Democrats, which is precisely what makes the result resonate beyond the five boroughs.
Because the districts are heavily Democratic, the primary winners are strong favorites to take their seats in the general election, meaning the sweep is likely to translate into a bloc of new socialist-aligned voices in the House. For incumbents elsewhere who had assumed the insurgent wave crested with Mamdani’s mayoral win, the message from New York is that it is still building.