NEW YORK — Following Diana Moreno’s decisive victory in the Queens special election, the political landscape appears far less certain for other candidates backed by New York City Mayor Zohran Mamdani. Moreno’s triumph may represent the last straightforward win for Mamdani-aligned politicians as more contentious races loom on the horizon.

Mayor Mamdani, who recently endorsed Brad Lander and Assemblymember Claire Valdez in their respective bids for Congress, faces a critical test of his endorsement power. With both races predicted to be fiercely competitive, the effectiveness of Mamdani’s support is now under scrutiny. “We’re testing that out,” noted Grace Mausser, co-chair of the Democratic Socialists of America’s New York City chapter, highlighting the substantial resources and influence Mamdani brings to a campaign.

Mamdani's involvement has varied between his endorsed candidates. He has been notably more active in supporting Valdez, appearing with her at events and creating engaging social media content to bolster her campaign. Valdez, a former union organizer and Queens lawmaker, is contending against Antonio Reynoso and Julie Won in a progressive district spanning Brooklyn and Queens.

On the other hand, Mamdani’s engagement in Lander's campaign has been minimal since his endorsement. Lander faces a tough challenge against incumbent Dan Goldman in New York’s 10th Congressional District, where Goldman holds a significant financial advantage and the support of key Democratic figures.

A political adviser to Mamdani, speaking on condition of anonymity, emphasized that while the mayor’s endorsements carry weight, his primary focus remains on governing New York City. This sentiment echoes the views of Democratic strategist Lupe Todd-Medina, who expressed concerns about Mamdani’s capacity to support his candidates effectively while managing the city’s complex needs.

The upcoming June primaries coincide with critical city budget negotiations, adding to the mayor’s substantial workload. The balance between political support and governance duties continues to be a delicate challenge for Mamdani, particularly as he faces criticism from established political figures like Rep. Nydia Velázquez, who has cautioned him to concentrate on his mayoral responsibilities.

As the political climate heats up with the approaching primaries, the strength of Mamdani’s endorsements will be pivotal in determining whether his candidates can navigate the increasingly turbulent waters of New York politics. The outcomes will not only affect the careers of Lander and Valdez but also test the limits of Mamdani’s influence in shaping the city’s political future.