Mayoral candidate Zohran Mamdani has been chatting with Chicago’s deeply unpopular far-left mayor — who Windy City voters recently warned is a posterboy for why New Yorkers shouldn’t elect a democratic socialist.

The New York City Democratic nominee fired off a friendly text message to set up a longer call with Mayor Brandon Johnson on July 11, according to records obtained by the Chicago Sun-Times.

“Hi Mayor Johnson, this is Zohran Mamdani. I just called, looking forward to chatting,” Mamdani wrote, according to the paper.

The eventual six-minute call was for Johnson to congratulate the socialist Queens assemblyman on his primary victory over the summer, a source from Mamdani’s camp told The Post. 

The pair of progressive pols didn’t discuss an endorsement, the source said.

Dubbed “America’s worst mayor” by the Wall Street Journal’s editorial board, Johnson has drawn comparisons to Mamdani for their shared progressive stances.

Some of Johnson’s policies have been playing out disastrously in Chicago with everything from massive budget woes to broken promises.

In June, the Chicago Tribune’s editorial board printed a stark warning to New Yorkers about electing a socialist mayor like Mamdani.

“A familiar dilemma: a moderate, business-friendly Democrat versus a democratic socialist. New Yorkers, take it from Chicago — we’ve seen this movie before, and the ending isn’t pretty,” the big city daily’s board wrote.

“Johnson’s approval rating cratered in his second year — a reflection of how quickly progressive promises collapsed under the weight of governance and Chicago’s financial reality,” the paper wrote. “What sounded good in theory has translated into dysfunction, driven by fiscal missteps and political inexperience.

The paper pointed out that many of Mamdani’s ideas — including rent freezes, city-operated supermarkets and free transit — are “shared (at least in principle) by Mayor Brandon Johnson, and many of them are popular in blue cities.”

“Johnson is one of the most progressive mayors in the U.S., but Mamdani, inarguably, is yet more radical,” it declared.

Some Chicago voters also said they regret supporting the embattled far-left mayor, and warned Big Apple residents not to make the same mistake.

“What I would say to New Yorkers is do your homework. You have to know who you are supporting, who you are voting for, so people of New York don’t walk around feeling the way I do,” said Cata Truss, a Johnson voter and campaigner turned critic.“I have buyer’s remorse in a way that I’ve never had before.”

A rep from  Johnson’s campaign also told the Sun-Times the call was to congratulate Mamdani and wish him “the best of luck.”