Three candidates backed by New York City Mayor Zohran Mamdani won their Democratic congressional primaries Tuesday, defeating three incumbent or favored establishment Democrats in a significant test of the mayor's political influence just six months into his tenure.

Mamdani, a democratic socialist who shocked the political world by winning the NYC mayoral race last year, campaigned extensively for all three candidates. The victories signal the growing reach of progressive politics within the Democratic Party and immediately became ammunition for Republicans heading into this year's midterm elections.

What the Left Is Saying

Progressive Democrats celebrated the results as a mandate for change. Rep. Ro Khanna of California, a potential 2028 Democratic presidential contender, said the outcomes "shows we have a new party."

In her victory speech, Claire Valdez — who defeated Brooklyn Borough President Antonio Reynoso by more than 20 points to succeed retiring Rep. Nydia Velazquez — declared: "Tonight, we haven't just won an election. We have declared that this movement is durable -- that it is growing, and that it will not stop until working people are no longer asked to just build the table, no longer just offered a seat at the table, but will run the table."

Brad Lander, who defeated incumbent Rep. Dan Goldman after previously running against Mamdani in last year's mayoral race, emphasized economic messaging centered on affordability in one of the nation's most expensive cities. Speaking about foreign policy positions shared by all three candidates, Lander said: "You can criticize Israel and not be antisemitic. You can be an anti-Zionist and not be antisemitic."

Mamdani told supporters at Valdez's celebration: "Let's hear it for a politics...that will never forget working people. For a politics that is ready to write a new chapter in our party's history, and for a politics that realizes the old politics that got us to this crisis, is not the politics that's going to get us out of this crisis."

Progressive groups argued the results demonstrate voter appetite for candidates focused on kitchen-table issues like housing costs and healthcare access.

What the Right Is Saying

Republicans quickly seized on the outcomes as evidence of Democratic Party radicalization. The National Republican Congressional Committee issued a statement calling it "the night the Democrat establishment officially surrendered to Zohran Mamdani and the socialist wing of their party."

NRCC spokesman Mike Marinella argued: "Every House Democrat, in safe and competitive districts alike, will now answer to the radicals calling the shots. And Americans should be terrified by where the Democrat Party is headed."

Conservative commentators noted that all three winning candidates were critical of Israel, with Chevalier described as having a history of anti-American rhetoric — a characterization her campaign has not directly addressed.

Republicans pointed to the victories as proof that Mamdani's influence extends far beyond New York City and suggested vulnerable House Democrats in competitive districts will face difficult questions about whether they align with the party's new direction.

The GOP framed the results as a gift for their midterm messaging, arguing suburban moderate voters will be alienated by Democratic Party moves further left.

What the Numbers Show

In New York's 13th Congressional District, Darializa Avila Chevalier, a 32-year-old community organizer and democratic socialist, narrowly defeated incumbent Rep. Adriano Espaillat, 71, who had served for a decade and chaired the Congressional Hispanic Caucus. The race was called as a near-coin-flip outcome.

Claire Valdez, a state assembly member aligned with the Democratic Socialists of America, defeated Brooklyn Borough President Antonio Reynoso by more than 20 percentage points in the race to succeed retiring Rep. Nydia Velazquez — one of the most liberal members of Congress.

Brad Lander, former New York City comptroller, defeated five-term Rep. Dan Goldman. Lander had previously challenged Mamdani in last year's crowded mayoral Democratic primary before becoming one of his key supporters.

All three candidates ran on platforms emphasizing affordability in a city consistently ranked among the nation's most expensive for housing and cost of living.

President Trump also notched primary victories Tuesday, with Trump-backed candidate Anthony Constantino defeating state party-backed Robert Smullen in the upstate New York race to succeed Rep. Elise Stefanik.

The Bottom Line

Tuesday's primaries demonstrated that Mamdani has become a significant kingmaker within the Democratic Party just six months into his mayoralty. His ability to deliver three high-profile victories over established Democrats signals progressive candidates can defeat party-backed incumbents with sufficient organizing and resources.

For Republicans, the results provide concrete examples of Democratic Party leftward movement heading into midterm elections where they are defending a razor-thin House majority. GOP strategists are expected to feature Mamdani prominently in campaign messaging targeting moderate suburban voters.

What remains unclear is whether these New York City-based victories represent a broader national trend or a localized phenomenon driven by the city's unique political demographics. Democratic Party leaders will be watching upcoming primaries closely to gauge whether the progressive wave has staying power beyond deep-blue urban areas.