Mamdani-backed candidates sweep New York primaries, Kennedy heir loses race

Zohran Mamdani’s allies swept all three congressional primaries he entered on Tuesday, June 23, turning the New York vote into the first major test of whether his influence could move from City Hall into Congress. Brad Lander won the Democratic primary in New York’s 10th Congressional District, and Claire Valdez and Darializa Avila Chevalier also prevailed, giving Mamdani-backed candidates a clean run and helping push two sitting Democratic incumbents out of office.

The sharpest reminder of how quickly the field has shifted came in New York’s 12th Congressional District, where Jack Schlossberg, the grandson of John F. Kennedy, lost the Democratic nomination to Micah Lasher. Lasher, a New York State Assembly member and longtime political operative who describes himself as a nerd, had the backing of Rep. Jerry Nadler. The result showed that a famous family name was not enough to overcome a hyper-local campaign built around neighborhood politics and a narrower Democratic coalition.

Election Day was Tuesday, June 23, 2026, with polls open from 6:00 a.m. to 9:00 p.m. New York also gave voters nine days of early in-person voting before Election Day, a window that has become part of the state’s regular primary and general election calendar. Even with that extended schedule, Mamdani’s intervention held across all three races, reinforcing that his political operation can still deliver in city and congressional contests alike.

The results carried added weight because Mamdani’s own 2025 Democratic mayoral primary win had already shown the reach of his coalition. He used ranked-choice voting to assemble a majority and posted the highest Democratic mayoral primary vote total in more than 36 years. The June 23 races suggested that the same left-populist network, including democratic-socialist candidates such as Valdez and Avila Chevalier, was becoming a more organized force inside New York Democratic politics rather than a single candidate’s brand.

The New York primaries were part of a broader June 23 election day that also included contests in Maryland, South Carolina and Utah, but the state’s races drew the most attention because of Mamdani’s imprint and the defeat of Schlossberg, who carried one of the most recognizable surnames in American politics.