By now you've probably heard it.
"The third agency of government I would do away with, the education, the commerce, and let's see. I can't, the third one I can't. Sorry."
Brandon Rottinghaus is an associate professor of political science at the University of Houston. He says huge mistakes like that will be hard to overcome.
"Candidates have got to be on their 'A game' and if they're not, then they have to find a way to minimize the damage they can do. You look at this sort of effect, whether it be in a debate or whether it be in a press conference or other kinds of high profile events and you start to wonder about the competence of the campaign, about the quality of the candidate and whether or not they have an actual chance of winning a nomination."
He says Perry isn't the only candidate to have bad things happen in high profile situations.
"All candidates go through these kinds of problems. You see what's happening with Herman Cain. Mitt Romney has been through this, Michelle Bachman has been through this. The real objective here for the Perry campaign and for any campaign is to try to minimize the damage that results from this. The problem seems to be that these kinds of events seem to be multiplying and you can only handle some many of these kinds of problems back to back and still survive in a nomination fight like this."
Rottinghaus says Perry's campaign should stress that he's not a polished debater and that his strengths among GOP voters are his conservative principals.