Mamdani-backed candidates sweep New York Democratic primaries in blow to party establishment

Three congressional candidates endorsed by New York City Mayor Zohran Mamdani swept Tuesday's Democratic primaries, toppling two incumbent lawmakers and an establishment-favoured candidate in results that have sent shockwaves through the national Democratic Party.

Former city comptroller Brad Lander, community activist Darializa Avila Chevalier, and state assemblywoman Claire Valdez all claimed victories, completing what has been described as a clean sweep for Mamdani's growing political operation.

The wins came less than seven months after Mamdani himself defeated former Governor Andrew Cuomo to become the youngest mayor of New York City in a century.

Lander defeated two-term Democratic congressman Dan Goldman in New York's 10th congressional district by 65.7% to 34.1%, with most votes counted. Goldman had led the House Democratic counsel team during Donald Trump's first impeachment trial in 2019 and had the financial backing of AIPAC, the pro-Israel lobbying organisation.

Chevalier, a doctoral student who has participated in pro-Palestinian protests at Columbia University, defeated Adriano Espaillat in the state's 13th congressional district, which covers Upper Manhattan and parts of the Bronx. Espaillat, 79, had held the seat for five terms and chaired the Congressional Hispanic Caucus.

Valdez defeated Antonio Reynoso, Brooklyn Borough President and the preferred successor of retiring Democratic Representative Nydia Velázquez, in the 7th congressional district, covering parts of Brooklyn and Queens.

Because all three seats are in reliably Democratic areas of New York City, the primary victories make the candidates virtual certainties to enter Congress following the November general election.

Divisions over Israel laid bare

The results threw into sharp relief the fault lines running through the Democratic Party over the conflict in Gaza. Lander has publicly accused Israel of genocide. Goldman, by contrast, was backed by pro-Israel groups — a position that drew protests, including from a Brooklyn coffee shop that posted on social media that the congressman was unwelcome.

Goldman accepted his defeat with a concession call to Lander. "Tonight, the voters of the 10th District have spoken. While this is not the outcome I worked so hard for, I respect their decision," Goldman said.

All three candidates backed by Mamdani have called for abolishing Immigration and Customs Enforcement (ICE), raising taxes on the wealthy, and have accused Israel of genocide — a charge Israel denies.

Mamdani described Chevalier as a person "of clarity, of conscience and of conviction." He told supporters at a watch party: "The old politics that got us into this crisis is not the politics that's going to get us out of this crisis."

Reaction from Washington

The results drew swift reactions from across the political spectrum. Trump posted on social media in the early hours of Wednesday, writing that America would "never be a communist country," and later described the three winners as "solid Communists" — a label that echoes his repeated characterisation of Mamdani during last year's mayoral race, a charge Mamdani has rejected.

House Democratic leader Hakeem Jeffries, who himself represents a portion of New York City, sought to minimise the significance of the results for his caucus. "We have agreed to strongly disagree," Jeffries said of his relationship with Mamdani. "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 prospect of Mamdani's allies joining the House Democratic caucus has nonetheless raised questions about whether they would support Jeffries in any bid for the speakership, should Democrats win a House majority in November. Neither Chevalier nor Valdez has stated a position.

Chevalier's past social media posts — including calls for a world with open borders, no prisons, and no police, made between 2018 and 2022 — have drawn rapid criticism from Republicans and some Democrats. She has disavowed those remarks, describing herself as a more mature person now.

Former Democratic National Committee chair Jamie Harrison was blunt in his response. "If you hate the Democratic Party, then please don't run for our nomination," he wrote on the social media platform Bluesky.

Lander pushed back on comparisons to the right-wing Tea Party movement. "We're joyful about what it looks like to deliver," he said in a television interview on Wednesday. "That is very different energy than what the Tea Party brought. We want to build something, not just break something."

A movement with national implications

The sweep was widely seen as a test of Mamdani's political capital beyond his own electoral coalition — and one that he passed. The endorsements carried weight in constituencies far broader than the base that elected him mayor.

Lander also received an endorsement from Vermont's democratic socialist Senator Bernie Sanders, adding further national momentum to the progressive flank.

In other races on Tuesday, however, centrist and moderate Democrats prevailed in several districts, underscoring that the national terrain ahead of November remains contested. Swing-seat incumbents Tom Suozzi and Laura Gillen on Long Island fended off primary challenges, and Cait Conley, a former White House counter-terrorism official and army combat veteran, won a competitive primary in the Hudson Valley's 17th congressional district — considered one of the most vulnerable Republican-held seats in the country.

In Maryland, Adrian Boafo won a crowded primary to succeed Steny Hoyer, the longest-serving House Democrat. In Utah, former congressman Ben McAdams, a political moderate, claimed the primary for a newly drawn Democratic-friendly district.

Jack Schlossberg, the grandson of former President John F Kennedy, lost his bid for New York's 12th congressional district to Micah Lasher, a longtime aide to retiring representative Jerry Nadler. Anti-Trump conservative George Conway also ran in that race, managing approximately 6% of the vote.

The results suggest a Democratic Party still grappling with its direction as it heads into November and towards the 2028 presidential cycle — a race that Mamdani has said he hopes to help shape through his growing network of endorsed candidates.