Former President Donald Trump took aim at Sen. Jon Tester (D-Mont.) over the weekend, telling supporters he “looks pregnant,” among other insults about the senator’s weight.

Trump made the offensive remarks at a private event at his Mar-a-Lago club and residence in South Florida during a fundraiser for Rep. Ronnie Jackson (R-Texas), who was Trump’s White House physician.

“He’s now in a tough campaign, and he could very well lose. We ought to go up and campaign against him,” Trump said about Tester, according to a recording of the remarks obtained by The Washington Post and Politico. “In fact, I looked at him, and I said, ‘Oh, this finally works for a man or woman, because he looks pregnant to me.’”

“Have you seen this guy? He doesn’t look like a fat guy, except his stomach is out to here,” Trump said to laughter. “Not that I talk about things like that. I don’t even notice them.”

A Trump campaign adviser defended the remarks in a statement to the Post, saying it wasn’t offensive to compare Tester to a pregnant woman because, “according to the left, men can” get pregnant.

“So where is the controversy?” the adviser, Chris LaCivita, told the newspaper.

Republicans have unleashed rampant attacks against transgender Americans during the past two elections, unveiling bills targeting health care for trans youth, access to bathrooms and limitations on participation in school sports around the nation.

Tester is one of the most vulnerable Democrats in the November elections as Republicans hope to flip several seats in the Senate to gain control of the chamber. Trump handily beat President Joe Biden in Montana in 2020, by more than 16 percentage points, and Tester is the only Democrat who holds statewide office there.

Trump has endorsed his Republican opponent, Tim Sheehy, and suggested to the crowd at Mar-a-Lago that he could travel to Montana to campaign for him.