The June 2025 Democratic primary in New York shocked many on the U.S. left. Zohran Mamdani, a self-proclaimed socialist and member of the Democratic Socialists of America (DSA), defeated former governor Andrew Cuomo to secure the party’s nomination for mayor. Supporters quickly declared the result a major breakthrough for the socialist movement. However, this development is less a victory than it is a reflection of a broader contradiction facing the U.S. left: the attempt to reconcile socialist rhetoric with participation in a party fundamentally loyal to capital.