5 Takeaways From the New York City Mayoral Primary

Zohran Mamdani, a state assemblyman who campaigned relentlessly against New York’s spiraling affordability crisis, was on the verge of a seismic upset in the Democratic primary for mayor on Tuesday, powered by a diverse coalition from brownstone Brooklyn to the immigrant enclaves of Queens.

The result was not final. But Mr. Mamdani, a 33-year-old democratic socialist, declared victory, and Andrew M. Cuomo, his rival and the former governor, conceded defeat.

Mr. Mamdani’s success in one of the first major Democratic primaries since President Trump returned to the White House reverberated across the country and offered a potential road map for Democrats searching for a path back to power.

The Democratic primary winner would typically be considered the front-runner in November’s general election. Yet this fall’s contest promises to be unusually volatile. It will include Mayor Eric Adams, who is running as an independent. Mr. Cuomo also still has the option of running on a third-party ballot line, though he has not committed to continuing his campaign.

Here are five takeaways from the primary:

Mamdani’s exuberant optimism attracted disaffected New Yorkers.

Mr. Mamdani, a third-term lawmaker from Queens, entered the race last fall with a thin résumé, virtually no citywide profile and views well to the left of many Democrats. He ended Tuesday as a breakout national figure.