Mamdani, 33, a two-term Queens assemblyman, replicated on a citywide scale what fellow socialist Rep. Alexandria Ocasio-Cortez accomplished in one congressional district when she toppled former Congressman Joe Crowley in the 2018 Democratic primary, with a new coalition that included younger voters.

Progressives see Zohran Mamdani as a candidate who can lead them to greater electoral success. Republicans see another chance to label the party as extreme.