A small coffee shop chain in New York City created a firestorm with a provocative social media post condemning a congressman who visited one of its branches on Sunday, further underlining tensions over support for Israel in one of New York’s most progressive and predominantly Jewish congressional districts.

The congressman, Dan Goldman, visited Poetica Coffee in Williamsburg, Brooklyn, outside his district, with his 7-year-old daughter on Sunday, the last day for voters to cast early ballots in a Democratic primary race where he is facing a strenuous challenge.

Hours later, Poetica put up an Instagram post that appeared to be written by the shop’s owner that made it clear, in harsh language, that he was unwelcome there.

“We see that you stopped by our shop today for a coffee,” the caption reads under a photo of Mr. Goldman looking at his phone in front of the shop’s cash register, an image that appeared to have been taken from a surveillance camera. “Do you see how it doesn’t taste like genocide juice? Or are you still having a hard time telling the difference?”

The post continued, “We don’t serve racists, fascists, homophobes, genocide enablers or anyone in between. Too bad we didn’t recognize you right away, or we would have turned you away.”

Mr. Goldman, whose defense of Israel has become a divisive issue in his bid for re-election in the 10th District, in parts of Lower Manhattan and Brooklyn, responded to the post in its comments, noting that he visited Poetica so that his daughter could use the restroom but purchased a coffee to thank one of its employees for allowing her to do so.

“The barista could not have been nicer to my 7-yr-old daughter and me,” he wrote. “I made sure to buy a coffee in return for her kindness. I hope you at least make sure that she gets the tip that she deserved.”

By Monday, the post was no longer visible: The Instagram account appeared to have been deactivated. But images of the post, as well as Mr. Goldman’s reply, were widely circulated on X, leading to criticism of Poetica on social media and in some new Yelp reviews.

The post and the reaction to it captured the volatile and at times petty manifestations of voters’ opinions about Israel and political candidates’ support for the country, days before a primary election largely animated by the conflict in the Middle East.

Mr. Goldman has drawn the ire of the left for his support of Israel while in Congress. He has received the support of American Israel Public Affairs Committee, the pro-Israel lobbying group, and was forced to answer questions about his wife’s social media behavior, which appeared to elevate right-wing pro-Israel talking points.

But Mr. Goldman, who declined a request for comment, has seemed cognizant of how his views on Israel may alienate some voters in his district, which runs from the East Village through affluent Brooklyn neighborhoods. He has not accepted direct AIPAC funding in his re-election campaign, though he does accept contributions from individuals funneled from the group’s website. He has voted to reject additional aid to Israel for the last two years, but he has declined to ban aid to the nation altogether.

Mr. Goldman, a Levi Strauss heir, is self-funding his campaign. His opponent, Brad Lander, the former city comptroller, has made his criticisms of Israel and condemnation of its conduct in the war with Hamas the foundation of his campaign message.

In a statement, Mr. Lander said, “There are plenty of ways to lobby elected officials and express outrage at the votes they’ve taken without turning coffee shops into places people don’t feel welcome.”

“I’m glad Poetica took down their post, and I thought Rep. Goldman’s reply was extremely gracious.”

Poetica’s owner, Parviz Mukhamadkulov, deleted his personal Instagram page on Monday, after the shop’s post about Mr. Goldman was publicized by the Washington Free Beacon, a conservative news outlet. He could not be reached for comment.

On the coffee shop’s website, it says it promotes “radical hospitality” that is “rooted in the Uzbek tradition where the guest is sacred, the books are unbanned and the door is open to everyone.”

Mr. Goldman’s volunteers have launched canvasses from Poetica’s locations in the district, and his staff members have worked from there during the primary, a campaign spokesman said.

But in Poetica’s Instagram post, the shop claims that it issued a refund to Mr. Goldman for his purchase, saying “we don’t need your money (it’s probably coming from AIPAC anyways).” It ends with an edict: “Enjoy your loss on Tuesday. Don’t ever come to Poetica.”

The 10th District has been the backdrop of a number of heated debates about support for Israel. Last month, members of the Park Slope Food Co-Op voted to boycott Israeli goods — a measure that supporters viewed as a moral stand in favor of Palestinian rights but opponents criticized as a move to alienate Jewish New Yorkers in the area.