Mamdani-backed leftists challenge New York Democrats in key primaries

Zohran Mamdani’s first major congressional test as mayor comes down to whether his name can move votes beyond New York City Hall. In three Democratic primaries on Tuesday, his endorsed candidates are trying to translate his political brand and the Democratic Socialists of America’s organizing into wins against entrenched incumbents and establishment-backed challengers.

Mamdani has lined up behind former New York City Comptroller Brad Lander in the 10th Congressional District against Rep. Dan Goldman, Queens Assemblymember Claire Valdez in the open 7th District seat vacated by Rep. Nydia Velázquez, and community organizer Darializa Avila Chevalier in the 13th District against Rep. Adriano Espaillat. Early voting ran through June 21, and the races are being watched as a measure of whether Mamdani’s mayoral victory can produce coattails for the broader left.

The clearest sign of how seriously Mamdani is taking the fight came at Kings Theatre in Brooklyn on June 18, when he and Sen. Bernie Sanders headlined a get-out-the-vote rally for Lander, Valdez and Avila Chevalier. Speakers at the event attacked incumbency as a substitute for action, criticized super PAC spending, and singled out the American Israel Public Affairs Committee, even though there was no visible spending from its independent expenditure arm in these races. Mamdani also argued that his endorsed candidates represent the future of the Democratic Party.

The 7th District has become a particularly sharp test of that claim. Valdez, who has the backing of the New York City chapter of the Democratic Socialists of America, has campaigned in Bushwick and Williamsburg, neighborhoods central to the district’s progressive base. She also appeared with Mamdani at the Knickerbocker Avenue Puerto Rican Day Parade. The race has been framed in part as a contest between Valdez and Brooklyn Borough President Antonio Reynoso, with Velázquez backing Reynoso.

In the 10th District, Lander’s bid against Goldman has been cast as a serious challenge to a sitting member of Congress, while the 13th District pits Avila Chevalier against Espaillat with House Minority Leader Hakeem Jeffries campaigning alongside the incumbent. Jeffries’ involvement signals how quickly the contests have become a proxy fight inside the party, with the left trying to prove it can convert activist energy into congressional power and the center trying to stop the spread of Mamdani’s model.

The open 12th District race adds another layer of uncertainty. Jerry Nadler’s retirement opened the seat and drew a crowded field that includes Assemblymembers Micah Lasher and Alex Bores, along with Jack Schlossberg and George Conway. Together, the primaries are testing not just Mamdani’s political capital, but the ceiling of the left inside Democratic politics in New York and, potentially, beyond.