Mamdani-backed candidates notch major primary wins in New York City

Zohran Mamdani’s backed candidates swept three congressional Democratic primaries in New York City, with Darializa Avila Chevalier delivering the sharpest blow by defeating five-term Rep. Adriano Espaillat in the 13th Congressional District. The result in one of the city’s most closely watched contests signaled that the Democratic Party’s left flank is not only organizing around ideology, but also converting local frustration into votes.

Espaillat’s loss carried added weight because he chaired the Congressional Hispanic Caucus and had spent five terms in the House. In the 13th District, Avila Chevalier advanced to the general election on Nov. 3, 2026, after a campaign that put a democratic socialist label at the center of a race once seen as an uphill fight against an entrenched incumbent. CBS News described the outcome as a stunning upset and a political earthquake for New York City politics and the Congressional Hispanic Caucus.

Avila Chevalier was not alone. Brad Lander and Claire Valdez also won their Democratic congressional primaries in New York City on June 23, giving Mamdani a clean sweep among the candidates he had backed. CBS News said the three victories showed Mamdani’s growing influence in New York Democratic politics, and CBS New York projected that all three were set to win after Mamdani endorsed them as left-of-center contenders. The alignment mattered: Lander also had the backing of Sen. Bernie Sanders and Rep. Alexandria Ocasio-Cortez, placing the contests squarely inside the broader progressive ecosystem.

The New York races are now being read as part of a larger test heading into the 2026 midterms, when control of both chambers of Congress will be at stake. Primary elections are running through the spring and summer in all 50 states, giving progressives and democratic socialists a chance to prove that affordability, labor and anti-establishment messages can beat better-known incumbents and mainstream Democrats. The New York results came days before another left-wing breakthrough, when Melat Kiros defeated incumbent Rep. Diana DeGette in Colorado’s 1st Congressional District Democratic primary on June 30.

That pattern has sharpened attention on the Democratic Socialists of America’s role inside the party. Ballotpedia notes that DSA is not a ballot-line party, so its members and endorsed candidates usually run as Democrats, or occasionally with other parties. It also says national DSA and local chapters can endorse candidates, a structure that helps explain how a faction with a relatively small formal footprint can still shape primaries, build coalitions and, in places like New York City, move from influence to wins.