State Democratic Chairman Jay Jacobs’ refusal to back socialist Zohran Mamdani’s mayoral bid is turning the party’s ideological rift into a full-blown crater — as lefties call on the longtime boss to resign and moderates hail his “common sense” take.

Moderate mayoral candidates Eric Adams, the incumbent, and Andrew Cuomo, the former thrice-elected Democratic governor, were among those praising Jacobs on Friday for standing up to Mamdani’s radical views.

But support from the pair – who are Dems running as independents – was arguably lost in the progressive blowback against Jacobs for bucking newfound Mamdani backer Gov. Kathy Hochul and failing to endorse the party’s nominee in the nation’s largest city.

“Disgraceful. The Chair of the Democratic Party refusing to support the candidate clearly selected by the voters of the Democratic Party,” state Sen. Michael Gianaris, a progressive, posted on X “If he won’t perform that most basic responsibility of a party leader, what exactly is he doing over there?”