DSA-Backed Candidates Win Three New York City Congressional Primaries, Backed by Mayor Mamdani

Since Zohran Mamdani won the New York City mayoral race last year, the central question has been whether his influence would hold beyond his own ballot line. Tuesday's primary results answered that.

What Happened

All three congressional candidates Mamdani endorsed won their primaries, according to The Guardian and Salon. Former city comptroller Brad Lander defeated Rep. Dan Goldman in New York's 10th District by roughly 31 points, according to Salon. State assembly member Claire Valdez beat Brooklyn Borough President Antonio Reynoso in the 7th District by approximately 19 points. And in the race that attracted the most national attention, public defense investigator Darializa Avila Chevalier toppled five-term Rep. Adriano Espaillat — chair of the Congressional Hispanic Caucus — in the 13th District by around 3.5 points.

Of the ten DSA-endorsed candidates who ran for office in Tuesday's primaries, nine appear to have won, according to Salon.

The Scope of the Sweep

This was not a narrow win in one sympathetic district. The DSA ran the board across multiple districts with very different demographics: Upper Manhattan, the Bronx, Brooklyn, and Queens all saw DSA or Mamdani-aligned candidates beat incumbents or establishment successors.

Salon noted that at one point on Tuesday, it was impossible to walk down the street in New York's 7th District without being handed a flier for a DSA-backed candidate. That ground game, organized by DSA's national and local infrastructure, is the operational story behind the headline numbers. Rep. Alexandria Ocasio-Cortez's profile energizes volunteers. The door-knocking gets people elected.

Beyond the marquee races, WNYC reported that some DSA-aligned candidates also made inroads upstate, a possible sign that the movement is beginning to expand its geographic footprint beyond New York City.

What It Means for Mamdani

Mamdani declared at Valdez's watch party, according to The Guardian: "The old politics that got us into this crisis is not the politics that's going to get us out of this crisis." Brad Lander, appearing with Mamdani in Brooklyn, told his crowd: "What a glorious time to be a New Yorker."

Mamdani's three-for-three endorsement record transforms him from a municipal leader into a genuine kingmaker at the federal level. With deep-blue New York City congressional districts nearly certain to elect Democrats in November, all three candidates are heavily favored in the general election.

The Races That Didn't Go DSA's Way

The 12th District followed different dynamics. Micah Lasher, described by The Guardian as a longtime New York politician and self-described "nerd," won the primary to succeed longtime Rep. Jerry Nadler. The race drew outsized national attention partly because of JFK's grandson Jack Schlossberg, 33, who tried to convert a large social media following into votes and came up short. Anti-Trump critic George Conway also ran and lost. Lasher will be the heavy favorite in November in a safely Democratic district.

Salon noted that Alex Bores, the candidate who became the focal point for what observers called an "AI civil war" within the Democratic Party, also lost to Lasher. The 12th District's voters skewed liberal rather than left-wing, which explains the different outcome.

The Strongest Counter-Argument

Critics of the DSA's rise have a fair point: New York City primaries are decided by a small, highly engaged electorate that skews far left of the national median. Voter turnout in these races is typically low. Espaillat lost by 3.5 points in a race covering Upper Manhattan and parts of the Bronx, a thin margin that a different turnout model could have reversed. Projecting Tuesday's results onto the national Democratic Party or onto general elections in swing districts requires a significant leap. The DSA's ground game is formidable in its home turf. Whether that model scales to contested territory is an open question.

Incumbents lost. Espaillat chaired the House Hispanic Caucus and had held his seat for five terms. Goldman was an incumbent with national name recognition. Those are not paper-thin opponents.

Not everyone paid a price for opposing progressives from the right. Some paid it for moving toward the center. According to Salon, state Sen. Jessica Ramos, who built her career as a progressive but endorsed former Gov. Andrew Cuomo for mayor last year, lost her re-election bid. That result signals that Mamdani's coalition has a long memory.

Donald Trump, for his part, celebrated Goldman's and Conway's defeats Tuesday night, according to The Guardian. His enthusiasm about DSA victories is an interesting wrinkle that neither Salon nor The Guardian examined closely. Trump's political interest in a more left-wing Democratic Party running House candidates in safe blue seats is worth watching as the November general election approaches.

The actual test of the three new DSA-aligned nominees may not come until they arrive in Washington and have to govern rather than campaign, depending on whether they face credible Republican challengers this fall.