Zohran Mamdani has won a decisive victory in the primary race to become the Democratic candidate for the next mayor of New York City, according to The Associated Press, after building a commanding lead in first-choice results that shook the national political establishment.

Mr. Mamdani roundly defeated Andrew M. Cuomo in the Democratic contest, widening his primary-night lead by a significant margin once ranked-choice tabulations were run.

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.