Republican presidential candidate Rick Perry did Wednesday night during a GOP debate.
His blunder? He couldn't remember the third federal department he would eliminate if elected President. Perry later insisted his gaffe wouldn't force him out of the Republican presidential field, noting that others have similar mistakes.
"The President of the United States said there were 57 states one time," Perry said in an Associated Press report. "Everybody makes mistakes."
He was referring to the comment President Obama made during a May 2008 campaign stop when he said, "I've now been in fifty -- seven states? I think one left to go."
Obama wasn't ridiculed too badly, as many chalked it up to travel fatigue.
During and after the blunder on Wednesday night, Perry shared a few laughs with his rivals on stage.
But according to the Associated Press, Perry's mistake was the worst in a series he's made over the course of six presidential debates, playing into stereotypes that the Texas governor isn't smart enough or qualified enough to be President.
Perry will make an appearance on the David Letterman Show Thursday night and will most certainly address his big "whoops" moment.