Mamdani-backed challengers defeat NYC political heavyweights in primary shakeup

Darializa Avila Chevalier, Brad Lander and Claire Valdez scored major victories, strengthening Mayor Zohran Mamdani’s growing influence ahead of the midterms.

Candidates backed by New York City Mayor Zohran Mamdani secured a series of high-profile victories in New York’s Democratic congressional primaries. They defeated several establishment-supported opponents and strengthened the political influence of Mayor Zohran Mamdani. The results are being viewed as an important test of the growing strength of progressive and democratic socialist candidates within the Democratic Party ahead of November’s midterm elections.

Among the most closely watched races was the defeat of Representative Adriano Espaillat, a five-term congressman and chair of the Congressional Hispanic Caucus. As reported by Al Jazeera, he lost to Darializa Avila Chevalier, a Democratic Socialist candidate who previously helped organize pro-Palestinian demonstrations at Columbia University.

In another major upset, Representative Dan Goldman was defeated by former New York City Comptroller Brad Lander, a longtime progressive figure who has frequently aligned himself with democratic socialist causes.

Meanwhile, New York State Assembly Member Claire Valdez, another Mamdani-backed candidate, defeated Brooklyn Borough President Antonio Reynoso in a race for a congressional seat being vacated by retiring Representative Nydia Velázquez.

The victories represent a significant political win for Mamdani, who actively campaigned for the challengers. The New York City mayor celebrated alongside supporters after the results became clear. “We are showing there is a new path for politics in our city and in our country,” Mamdani said during a victory event in Manhattan.

At another celebration in Brooklyn, Mamdani described the results as evidence of a growing political movement. “A year ago, it was not the end of a political movement. It was the beginning of one,” he told supporters.

The primary outcomes are particularly significant because many New York City congressional districts strongly favor Democrats, meaning primary winners are often well-positioned for success in the general election.

The results also dealt a setback to several establishment Democrats, including House Democratic Leader Hakeem Jeffries, who had supported candidates opposing Mamdani-backed candidates. Following the elections, Jeffries minimized the broader implications of the losses.

“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,” Jeffries said.

Not all races favored progressive challengers. In the contest to replace retiring Representative Jerry Nadler, Micah Lasher defeated a crowded field that included Jack Schlossberg, the grandson of former President John F. Kennedy. Mamdani did not endorse a candidate in that race.

The success of Mamdani-backed candidates is expected to fuel ongoing debate within the Democratic Party over its direction heading into the 2026 midterm elections. Supporters view the results as evidence of growing momentum for progressive policies, while some party leaders have expressed concerns about how the party’s ideological divisions could affect its national strategy.