NOVA YORK — Mayor Zohran Mamdani and his allies won a series of congressional races in New York on Tuesday (23), in a remarkable show of strength from the insurgent left that sent shockwaves through the Democratic Party.
Candidates supported by Mamdani defeated two incumbent MPs backed by establishment city politician, including major unions and the Democratic leader in the House. Another name backed by the mayor won a race for an open City Council seat, and some democratic socialist challengers he endorsed also led in other races on the ballot.
For months, Mamdani threw his energized political organization into the three main congressional races, campaigning late into the night in recent days and framing the election as a referendum on the party’s direction.
All of the victorious candidates shared Mamdani’s progressive economic platform and ran campaigns focused on ending U.S. support for Israel — a sign of how much public opinion has changed on this issue, including in New York.
On Tuesday night, the mayor appeared smiling at a victory party in Brooklyn, where supporters chanted “Free Palestine” and “DSA” (acronym for the socialist group within the Democratic Party). Surrounded by many of the same advisers who ran his victorious campaign last year, he declared the opening of “a new chapter in the history of our party.”
“A year ago, that wasn’t the end of a political movement,” he said. “It was the beginning.”
Continues after advertising
Mamdani’s involvement represented a bold gamble for a newly elected mayor trying to lead a city already marked by internal divisions. Along the way, he alienated important allies, but the political gains were broad.
At home, the result now tends to consolidate him as the main political guarantor of the US cultural and financial capital, in addition to reinforcing the Democratic Socialists of America (DSA) as a relevant force.
The results also shook the Democratic Party’s foundations far beyond New York’s five boroughs. If confirmed, Mamdani, 34, and his movement would be on track to double the number of socialists in Congress from two to four. The outcome will also force a Democratic Party, already in search of identity, to face the rise of its left wing, without apology.
Continues after advertising
“It’s seismic,” said Jon Paul Lupo, a Democratic consultant and former aide to the city’s last progressive mayor, Bill de Blasio.
The disputes do not necessarily mean that Mamdani has broadened his electoral appeal. All of the races in which he has made endorsements have been in areas where the mayor won handily last year and remains very popular.
But Tuesday’s results showed two things about his still young administration: Mamdani has a high tolerance for political risk, far above that of his recent predecessors. And, at least for now, he has the ability to transfer his strong political brand to other candidates in a way that few politicians in any position can.
Continues after advertising
Brad Lander, 56, a close ally whom Mamdani encouraged to run for Congress, opened up a stunning 30-point lead in the wealthy 10th District, which encompasses parts of Brooklyn and lower Manhattan. He defeated Representative Daniel Goldman, heir to the Levi Strauss fortune, who had opposed the mayor in last year’s election and had close ties to the American Israel Public Affairs Committee (Aipac), a pro-Israel lobby.
Claire Valdez, 36, little known and also recruited by Mamdani, obtained a better than expected margin to win the open seat in the 7th district, in a gentrifying strip between Brooklyn and Queens so far to the left that it earned the nickname “communist corridor”.
She defeated Antonio Reynoso, the Brooklyn borough president, who had much deeper roots in the region and the support of the popular retiring congresswoman Nydia Velázquez, as well as the progressive Working Families Party and virtually all of the city’s major unions.
Continues after advertising
Mamdani’s allies also won in the largely black and Dominican 13th District in northern Manhattan and the Bronx. In what was perhaps the biggest surprise of the night, 32-year-old Darializa Avila Chevalier, another democratic socialist who entered the race as a politically unknown figure, narrowly defeated Congressman Adriano Espaillat, the influential chairman of the Congressional Hispanic Caucus.
Mamdani’s aggressive interventions, however, did not come without collateral damage. His positions in some races have put him on a collision course with the Working Families Party, prominent black and Latino Democrats, major unions and City Council members — all supporters of his mayoral campaign and now involved in his governing agenda.
He deeply angered Nydia Velázquez, his first supporter in Congress, who believed the mayor should respect her preference on who would be her successor. She went on to accuse, in particular, the DSA of trying to erase the contribution she and other progressives made to pushing the city to the left over decades.
Others, including Hakeem Jeffries, the Democratic leader in the House, were even more upset when Mamdani decided in May to support Avila Chevalier and break with Espaillat.
Espaillat did not support Mamdani in last year’s caucuses, but later quickly endorsed him and helped bring part of the Latino electorate with him. At the time, Mamdani reportedly privately assured Espaillat that he would reciprocate this gesture if necessary.
The mayor never explained his change of position in detail, but his advisors said he saw Avila Chevalier’s progress and believed he could make a difference in the dispute. Espaillat’s allies were furious and said they could no longer trust Mamdani’s word.
Tuesday’s result could create particular problems for Jeffries, the New Yorker tipped to take command of the House if Democrats regain control of the House this year. Valdez and Avila Chevalier have not yet committed to supporting Jeffries’ leadership bid and could become recurring sources of pressure for him.
Democrats aligned with Jeffries, who worked to defeat Avila Chevalier, have already expressed guarded concern about his victory. The fear is that Republicans will use her inflammatory old social media posts — including a statement that “all deportations are wrong” and foul language about Kamala Harris — against more moderate Democrats who will contest swing districts for control of the House this fall.
Jeffries avoided going into the topic during an interview with NY1 on Tuesday night, as the results came in. Others, however, were more direct in expressing concern.
“Republicans will quickly try to elevate, as they always do, the most radical voices in the Democratic Party,” said Howard Wolfson, the former head of House Democrats’ election arm and a former top adviser to Michael Bloomberg. “And after tonight, they will have more radical Democrats to choose from.”
Mamdani and his allies see the situation very differently.
Gustavo Gordillo, co-president of the DSA in New York, said the organization has already turned its attention to next year’s budget dispute in Albany and its next steps.
“Let’s start thinking about 2028 and what comes after,” he said.
c.2026 The New York Times Company
