Three candidates endorsed by New York City's democratic socialist Mayor secured significant victories in key U.S. House primary races, marking a notable success for the progressive faction within the Democratic Party. These wins represent a blow to the party's establishment.

Among the successful candidates was Avila Chevalier, who was endorsed by Mayor Mamdani. Mamdani, speaking to Chevalier's supporters, highlighted her background and advocacy, stating, "I can think of no better person than the daughter of a single mother caseworker who has fought for working people her entire life, who has stood up for New Yorkers unjustly detained by I.C.E., who has called for a foreign policy of investing in babies and not bombs."

One of the races saw Representative Adriano Espaillat, who had the backing of prominent Democrats including House Minority Leader Hakeem Jeffries, concede his primary. Espaillat, the first Dominican-American elected to Congress, emphasized his advocacy against former President Donald Trump's immigration policies. "Tonight wasn’t our night, but I love you anyway," Espaillat told his supporters. He added that it was "the privilege of my life to serve you, the community, and I will continue to love and serve this community the best way that I can." When asked about Mamdani's endorsement of his opponent, Espaillat stated, "I respect the mayor’s decision."