In New York, Andrew Cuomo’s comeback after resigning in disgrace could end up taking less than four years – with a scandal-plagued incumbent mayor, a disorganized left wing and a feeling that the city is on the brink paving the way.

A government reform group is urging campaign finance regulators to investigate Andrew Cuomo’s relationship with a lobbying firm providing him free campaign services and to consider stripping the mayoral frontrunner of millions of dollars in public matching funds.

Mr. Cuomo told The New York Times in a wide-ranging interview that none of the sexual harassment allegations against him had merit.