Here's what was said:
Jack Cafferty: I like Obama. I think he's a bright guy. He's the former editor of the Harvard Law Review, former Senator, President of the United States, and he goes on The Tonight show and says arguably the stupidest thing he's ever said in his entire adult life.
Jon Stewart: The Special Olympics thing?
Cafferty: Yea
Stewart: It was crazy.
Cafferty: What makes people do that on talk shows?
You can watch the clip here.