The hotel workers' union and the building service workers' union represent more than 120,000 people in New York City.

Sources told CNN that Cuomo's team believes the general electorate could be more receptive to his candidacy than primary voters.

Zohran Mamdani's surge to the top in New York City's Democratic mayoral primary came with the help of an army of volunteers who set a goal of knocking on 1 million doors to get votes.