New York City’s political left is experiencing a moment of public friction as Mayor-elect Zohran Mamdani, a prominent democratic socialist, has taken an unexpected stand against a challenge from within his own ranks. On November 19, 2025, at a closed-door meeting of the Democratic Socialists of America (DSA) in Manhattan, Mamdani urged the group not to endorse Brooklyn City Council Member Chi Ossé’s primary campaign against House Democratic Leader Hakeem Jeffries. This move, coming just weeks after Mamdani’s own historic mayoral victory, highlights the complex balancing act now facing the city’s ascendant progressive movement.
The roots of this intra-party dispute stretch back to November 17, when Ossé, a recently minted DSA member and once a close ally of Mamdani, filed paperwork to run against Jeffries in the 2026 Democratic primary. The announcement sent ripples through New York’s political scene—Jeffries, after all, is not only the House Democratic leader but also a fixture in Brooklyn’s political establishment. According to The New York Times, Mamdani had worked for months to secure Jeffries’ support for his mayoral bid, a backing that was only made official shortly before the November 4 election. Mamdani’s victory, achieved on an affordability-focused agenda, was buoyed by this late but crucial endorsement.
Yet, as the dust settled from that contest, old alliances began to fray. Mamdani and Ossé, once seen as a united front for New York’s left, found themselves at odds over strategy and timing. In a PIX11 interview on November 19, Mamdani made his position clear: “I think that right now is not the time to be engaging in that kind of a primary. I think the focus should be on delivering on this affordability agenda,” he said, responding to whether Ossé should pursue his challenge. The statement marked the first time Mamdani had so publicly and explicitly urged his former surrogate to stand down.
Later that evening, Mamdani appeared before the DSA’s Electoral Working Group at the Church of the Village in Manhattan. According to sources who attended the meeting and spoke with the Daily News on condition of anonymity, Mamdani greeted the group with, “It is good to be home,” before laying out his pragmatic case. “The choice is not whether to vote for Chi or Hakeem at the ballot box, the choice is how to spend the next year. Do we want to spend it defending caricatures of our movement, or do we want to spend it fulfilling the agenda at the heart of that very same movement?” he argued. “I believe that endorsing [Ossé] makes it more difficult to do the latter, more difficult to deliver on the life-changing policies that more than 1 million New Yorkers voted for just two weeks ago.”
Mamdani’s message was clear: unity and focus were needed to enact the sweeping changes he had promised, not internecine battles that could sap the movement’s momentum. He continued, “I know how I want to spend the next year, and I urge you all to join me in voting no on this endorsement, not because our dreams are too small, but because they are as big as the entire city.” The DSA Electoral Working Group is expected to vote on whether to endorse Ossé’s run by Saturday, November 22.
The mayor-elect’s stance was echoed by Tascha van Auken, his campaign’s field director and a significant figure in the DSA. Van Auken questioned whether Ossé was truly committed to the group’s principles, noting that he only became a dues-paying member in the summer of 2025, after Mamdani’s mayoral primary win. Their arguments reflected a broader concern: that an endorsement of Ossé’s campaign could complicate the already delicate process of enacting the affordability agenda that had galvanized over a million voters.
Despite these reservations, the meeting was far from unanimous. Assemblywoman Emily Gallagher and Gustavo Gordillo, co-chair of the DSA’s New York City chapter, spoke in favor of backing Ossé. Supporters see Mamdani’s election as a launchpad for left-wing candidates to challenge centrist Democrats across the city. Ossé himself, in remarks to the group, acknowledged the skepticism but insisted his campaign was a matter of principle. He declared, “He cynically uses race as a shield, while he fails to fight fascism, sells out our communities, empowers conservative principles and funds mass slaughter,” referring to Jeffries. Ossé also touted $150,000 in pledged donations and promised to fight for “true socialism,” including Medicare for All, abolishing ICE, and a U.S. arms embargo on Israel.
The split is emblematic of a larger debate within the DSA and the city’s progressive circles: whether to prioritize coalition-building and legislative wins or to push for ideological purity and direct challenges to the party establishment. Political commentator Gerson Borrero, who supported former Governor Andrew Cuomo in the mayoral race, weighed in on social media, writing, “Sounds more and more like the politics Neoyorquinos have seen time and time again. @ZohranKMamdani does it his way to get to City Hall but @OsseChi has to follow his orders. So, how are socialists different? I must be missing something here.”
Mamdani’s concerns are not without precedent. According to The New York Times, he believes that a primary challenge against Jeffries—who is widely popular in his Brooklyn district and boasts a formidable fundraising operation—could backfire, putting at risk the very policies that brought the left to power. U.S. Rep. Alexandria Ocasio-Cortez, herself no stranger to primary upsets, told Axios on November 17 that she did not think challenging Jeffries at this moment was a “good idea.”
Still, the energy on the left is palpable. Ossé’s supporters argue that Mamdani’s victory should embolden the DSA to take on centrist Democrats more aggressively. Some point to the possibility of targeting Rep. Dan Goldman, another centrist, as a more viable test case for the movement’s growing influence. For now, however, Mamdani appears determined to keep the peace within the party, at least until his administration has a chance to deliver on its promises.
As the DSA weighs its endorsement and the city’s progressive movement debates its next steps, one thing is clear: the contest between pragmatism and principle is far from settled. For New Yorkers watching this drama unfold, the outcome will likely shape not only the city’s political landscape but also the broader trajectory of the American left in the years to come.
