NYC Mayor Mamdani risks political capital backing challengers to three incumbent lawmakers

Zohran Mamdani, the newly elected mayor of New York City, is spending his political capital in a way that could reshape the city's congressional delegation—or cost him dearly. In the spring of 2026, he announced endorsements for three candidates running against sitting Democratic lawmakers, a move that signals his intention to remake the federal representation from his city in the image of his democratic socialist movement.

The three races are straightforward in their stakes. Mamdani backed Brad Lander, the former city comptroller who worked alongside him during his 2025 mayoral campaign, to challenge Rep. Dan Goldman in a district spanning Manhattan and Brooklyn. In another Brooklyn and Queens seat, he endorsed state Assembly member Claire Valdez against Brooklyn Borough President Antonio Reynoso, who was himself backed by the retiring congresswoman, progressive Rep. Nydia Velázquez. And in a Bronx and Manhattan district, Mamdani threw his support behind Darializa Avila Chevalier, an activist and organizer, to run against Rep. Adriano Espaillat, the chairman of the Congressional Hispanic Caucus. The three candidates appeared together in an advertisement that aired during Game 1 of the NBA Finals between the New York Knicks and San Antonio Spurs, with Mamdani framing the endorsements as a team effort to fight for working New Yorkers and take on corporate greed.

These are not routine primary endorsements. The races pit different wings of the Democratic left against each other, with the Israeli-Palestinian conflict and attitudes toward Gaza serving as a defining fault line. Mamdani's candidates have made clear their positions: they describe Israel's conduct in Gaza as genocide and reject donations from groups or individuals tied to the American Israel Public Affairs Committee. The contests are also unfolding in districts where Mamdani himself routed former Governor Andrew Cuomo in November, and in neighborhoods experiencing rapid gentrification. Two of the races feature Mamdani's preferred candidates in their 30s, signaling a push for generational turnover alongside ideological realignment.

Mamdani's allies argue he is acting at precisely the right moment. He is broadly popular across the city and may never again wield as much influence in local politics. Rebecca Katz, a prominent Democratic strategist who worked with Mamdani during his mayoral run, called the move "high-risk, high reward," noting that he is willing to take major political swings. A Democratic strategist working to boost his candidates told NBC News that Mamdani's endorsement carries real weight in his districts and could prove decisive, particularly for candidates like Valdez who lack other sources of name recognition or institutional backing.

But the risks are substantial. Mamdani reportedly went back on a private commitment he made to Espaillat after the congressman dropped his support for Cuomo—a reversal that could make federal lawmakers wary of making deals with the mayor in the future. Bradley Tusk, an adviser to former Mayor Michael Bloomberg, argued that Mamdani is prioritizing his movement's ideological purity over his ability to govern effectively. If his candidates lose, the damage to his political standing could hamper his capacity to deliver for New York residents. If they win, he will have reshaped the city's federal delegation, but at the cost of relationships he may need to function as mayor.

The incumbents have largely declined to engage in direct conflict with the popular mayor. Espaillat said he respects Mamdani's decision and is confident in his own reelection. Goldman downplayed the endorsement's significance, emphasizing his working relationship with the mayor on shared priorities like waterfront development. Velázquez, retiring after more than three decades in Congress, echoed a concern raised by Espaillat: that elected officials need to maintain good relationships with the federal government, which controls budgets and resources critical to the city. Yet Katz countered that Mamdani would not be mayor if he operated by the old rules, and that his willingness to break with convention is precisely what brought him to power.

Avila Chevalier, one of Mamdani's endorsed candidates, has drawn scrutiny for her past social media posts, in which she called former President Joe Biden a rapist, criticized interracial relationships, and called for the abolition of police and prisons. She has said she has grown since those posts, which she deleted years ago when she closed her Twitter account. In an interview, she said her values have remained constant but her understanding of how to approach systemic change has matured. She expressed pride in Mamdani's endorsement, framing it as validation that her campaign represents a serious challenge to the incumbent.

The races will test whether Mamdani's movement can consolidate power beyond the mayoralty, or whether his endorsements will fracture relationships he needs to govern. The outcome will likely define not just the composition of New York's congressional delegation, but the trajectory of his own political career.