The Texas Republican was speaking at the Value Voters Summit, an annual gathering of social conservatives in Washington. He was telling a story about not taking the easy route in Congress, when he quipped: "When you look at the kind of people running for president, no-brainers are a good thing now."
But while that comment seemed to include Republican Donald Trump, he attacked Clinton's health exclusively.
"A true believer does what Jesus did ... you don't make fun of people who are impaired, have special needs, and whether you like her or not, Hillary Clinton's made clear, she is mentally impaired," Gohmert joked, to some laughter from the crowd.
Neither the Clinton campaign nor Gohmert's office immediately responded to CNN request for comment. The Texas Republican is no stranger to controversy, and is known on Capitol Hill for regularly having a sharp quip at the ready.
Seemingly invoking conspiracy theories about Clinton's health that have been debunked
, Gohmert referenced a concussion Clinton sustained in a fall in 2012 as his guess for the start of her "impairment."
"Maybe it was the concussion, the fall back when she did, or maybe who knows, they won't tell us what really is going on with her, but if I were going to smash cell phones, BlackBerrys, I'd use a two-pound sledge," he said, referring to a recent FBI report that said at least one of her phones as secretary of state was destroyed with a hammer. "Maybe someone got to whaling around, hit her again. We ought to be praying for Hillary Clinton. There's special needs there -- mental impairment."
Gohmert noted that earlier in the week he had made a comment that "Hillary's brain is in a blender," generating headlines. He blamed a song that conservative radio host Rush Limbaugh used to play that included a similar line.
But Gohmert, joking about not joking, reiterated the point.
"That was not a proper thing to say, because again, I'm making fun of the mentally impaired and that's not right," he said.