Mamdani-Backed Challengers Beat Two Incumbent House Democrats in New York

New York City Mayor Zohran Mamdani’s slate of progressive candidates swept Tuesday’s Democratic congressional primaries in the city, ousting two sitting House members and winning an open seat, according to NBC News, The Guardian and Al Jazeera. The results, which are expected to produce three more Mamdani allies in Congress in January because the districts are solidly Democratic, amount to a show of force for the democratic socialist mayor and a challenge to party leaders.

In the 10th District, former city comptroller Brad Lander defeated Rep. Dan Goldman, taking almost two-thirds of the vote, NBC reported. Goldman, who was lead counsel in Trump’s first impeachment trial and had endorsements from Gov. Kathy Hochul, House Democratic Leader Hakeem Jeffries and key unions, NBC said his greatest vulnerability among Democratic voters was the issue of Israel; he was backed by both the American Israel Public Affairs Committee and the liberal group J Street. The Guardian reported that Lander criticized AIPAC’s support for Goldman and promised to sponsor legislation restricting military aid to Israel.

Hours later, Rep. Adriano Espaillat, who chairs the Congressional Hispanic Caucus, lost to Darializa Avila Chevalier, a democratic socialist who has not held public office before, according to The Guardian and NBC. The Guardian noted that she once wrote a profane post on social media criticizing Kamala Harris. In the open 7th District, where Rep. Nydia Velázquez is retiring, state Assemblymember Claire Valdez, a Mamdani ally, beat Brooklyn Borough President Antonio Reynoso, whom Velázquez had endorsed, NBC reported.

Goldman is the fifth House incumbent to lose a primary so far in 2026, NBC reported, as voters express frustration with their party’s leaders. Mamdani told Valdez’s supporters, “A year ago, it was not the end of a political movement. It was the beginning,” and said at Avila Chevalier’s party that the results show “a new path for politics in our city and in our country,” Al Jazeera reported. Jeffries, who had campaigned against Mamdani’s candidates, downplayed the outcome on Capitol Hill: “We have agreed to strongly disagree. There are 215 members of the House Democratic caucus. A handful of primaries that go in one direction or the other, in a given state or two, aren’t going to reshape who we are as House Democrats.”

The results landed in a party debate over how far left to move before the November midterms. Al Jazeera wrote that the sweep is a potential headache for Democratic leaders who fear the Mamdani-aligned candidates could push the party too far left, while The Guardian argued that voters are signaling they want Democrats to stand for more than letters of protest. A Gallup survey last year found that 42 percent of Democrats view capitalism favorably and 66 percent view socialism favorably, the Guardian reported. The Guardian noted that democratic socialist candidates also won the Democratic primary for mayor in Washington, D.C., and made the runoff in Los Angeles.

Elsewhere on the New York ballot, establishment-backed Assemblymember Micah Lasher won the race for the seat Rep. Jerry Nadler is vacating, in a field that included Jack Schlossberg, anti-Trump activist George Conway and Assemblymember Alex Bores, whose artificial intelligence regulation proposals drew tech-industry spending, Al Jazeera reported. Mamdani had not endorsed in that race.