To best 10 candidates in the Democratic primary for mayor of New York City, Assembly Member Zohran Mamdani had to overcome an endorsement from a former president, attack ads from longtime billionaire donors and the name-recognition of a political dynasty.

Now appearing as the likely Democratic nominee after former Gov. Andrew Cuomo conceded, Mamdani faces a dual challenge: lukewarm support from the Democratic establishment and Cuomo’s apparent comeback attempt, reported by CNN, as an independent candidate.