New York City Mayor Zohran Mamdani cemented his status as one of the most influential figures in Democratic politics Tuesday night after all three candidates he endorsed in closely watched congressional primaries defeated better-known and better-funded establishment rivals, delivering a stunning rebuke to the party's old guard.
The victories by Brad Lander, Claire Valdez, and Darializa Ávila Chevalier represent the strongest demonstration yet of Mamdani's political influence since his upset victory in New York City's 2025 mayoral race. The trio, all aligned with the progressive and democratic socialist movement, overcame candidates backed by some of the most powerful figures in New York politics.
The biggest upset came in New York's 13th Congressional District, where Avila Chevalier defeated five-term incumbent Rep. Adriano Espaillat, one of the most prominent Latino Democrats in Congress and a longtime fixture in New York politics.
In the 10th District, former New York City Comptroller Brad Lander unseated Rep. Dan Goldman despite Goldman receiving support from House Democratic leadership and establishment figures.
Meanwhile, Claire Valdez prevailed in the race for New York's 7th Congressional District, defeating Brooklyn Borough President Antonio Reynoso and overcoming a coalition of traditional progressive and establishment Democratic organizations.
The sweep is likely to intensify comparisons between Mamdani and progressive power brokers such as Bernie Sanders and Alexandria Ocasio-Cortez, but with one major difference: Mamdani is now demonstrating an ability not only to win elections himself but also to deliver victories for others.
Political observers had viewed Tuesday's primaries as a test of whether Mamdani's appeal extended beyond City Hall. The answer appears to be yes.
The mayor personally campaigned for all three candidates, appearing at rallies, filming endorsements and presenting the races as part of a broader movement focused on affordability, housing costs and economic inequality. On election day, Mamdani publicly promoted the trio as candidates who would carry his agenda into Washington.
The results also highlight a growing power struggle inside the Democratic Party between a younger progressive wing and more traditional establishment leaders. House Democratic Leader Hakeem Jeffries had supported Goldman, while other party veterans lined up behind incumbents and more moderate candidates. Voters nevertheless sided with Mamdani-backed challengers.
For Mamdani, the victories represent a remarkable political transformation. Just two years ago, many national Democrats viewed the democratic socialist as a fringe figure. Today, he appears capable of reshaping New York's congressional delegation and influencing the ideological direction of the Democratic Party in its largest city.
The outcome is also likely to increase speculation about Mamdani's future role in national politics. With allies now heading to Congress and a growing coalition of young voters, renters and working-class New Yorkers behind him, Tuesday's results suggest that his influence may extend far beyond City Hall.
