Rand Paul mocks Rick Perry over debate flub

“If Gov. Perry decides to run for president, I think there would be three good reasons why he could be president: Texas is a big successful state, he’s a long term governor and … I can’t remember the other one,” Paul quipped.

The joke was a reference to Perry's disastrous performance in a November 2011 GOP presidential debate, in which he was unable to remember the third federal agency he wanted to eliminate.

"Commerce, Education and the — what's the third one there? Let's see," Perry said at the time.

Perry later acknowledged the gaffe — telling CBS News that he "stepped in it" — but his campaign was never able to recover. He later endorsed Newt Gingrich for the Republican nomination ahead of the South Carolina primary.