So the liars at the Washington Post are bringing up that falsehood again. In reality, it never happened.
I remember that episode of his tv show, though as I recall, he was talking about Bo and mentioned the “White House dog”, then his producer put up a pic of Chelsea. Who knows if Rush was in on it or not.
When it comes to Chelsea jokes, leave it to Senator Johnny “Crash” McCain, in 1998: “Do you know why Chelsea Clinton is so ugly?” he told a handful of GOP-e fat cats. “Because Janet Reno is her father.”