Zohran Mamdani has won New York City’s Democratic mayoral primary. A new vote count Tuesday under the city’s ranked choice voting system confirmed the progressive legislator’s stunning upset of former Gov.

Mr. Mamdani’s victory upended city politics and reverberated nationally. He relied on a memorable message, charisma and a strong ground game.

Mamdani, a democratic socialist, added to his margin of victory over former Gov. Andrew Cuomo after the ranked-choice votes were redistributed.