Why? Let's just say that the MSNBC host has a penchant for aggressively nudging his guests toward gaffe-worthy statements. O'Donnell has seemingly made a habit of asking his guests a question and then--before the guest can fully answer--interjecting "Wrong!" and pointedly explaining to them why their reasoning is so ill-conceived. So, when the host begins his interview with Goodlatte with the question "do you agree with everything the founding fathers wrote in the Constitution?" it's clear where the Q&A is headed.
Fast forward a few minutes in the clip (where it starts below) to where O'Donnell asks the Rep. if he believes the minimum wage is Constitutional. In effect, Goodlatte responds that he didn't know if it is a state or federal issue. "Then why did you vote for an increase in the minimum wage in the 110th Congress? You don't even know if it's Constitutional?" asks O'Donnell sternly. "Well, that's correct," Goodlatte began. That's where the newsworthy soundbite occurs (via Matt Schneider at Mediaite):
O'Donnnell: "You voted for an increase in something that you don't even know has Constitutional authority to exist?"
Goodlatte: "That's correct and that’s why it's good to reinstate this focus on the Constitution as we debate these bills. In the future a minimum wage bill will have to have in it a declaration of the section of the Constitution that gives the authority to increase the minimum wage..."