Mamdani-backed candidates score upsets in New York Democratic primaries

Zohran Mamdani’s congressional endorsees swept three New York Democratic primaries, unseating two sitting House members and giving the New York City mayor an early measure of clout beyond City Hall. In the June 23 contests, Brad Lander, Claire Valdez and Darializa Avila Chevalier all won after Mamdani backed each campaign.

The sharpest reversals came in New York’s 10th and 13th congressional districts. Lander defeated two-term Rep. Dan Goldman with about two-thirds of the vote, while Avila Chevalier beat five-term Rep. Adriano Espaillat, the chair of the Congressional Hispanic Caucus. Valdez won the open 7th District race to replace retiring Rep. Nydia Velázquez, completing a clean sweep for Mamdani’s preferred candidates.

The results landed as a rebuke to establishment Democrats in a city where primary victories often decide who goes to Washington. They also showed that Mamdani’s backing carried weight in the same districts where he performed especially well in his November 2025 mayoral victory over former Gov. Andrew Cuomo, who had the backing of top establishment Democrats.

Foreign policy toward Israel was one of the clearest dividing lines in the races. In victory remarks, Lander called for a change in the party’s approach to Israel and said Joe Biden’s support for Prime Minister Benjamin Netanyahu was a mistake. The campaigns also reflected a broader push from Mamdani’s democratic socialist wing for more aggressive economic policies, a message that helped turn three closely watched primaries into a test of where New York Democrats are heading next.