hahhahaha..how is the worlds biggest liar going to pull that off???
By doing it. The press will run cover for him. Obama will have to do something like this to try to push Mitt back on his heels. The fact that it's a lie won't matter. All that will be needed is for Obama to raise his voice and look stern. The press and spinners will then swoop in to gush that the "real" Obama is back and that he put Mitt in his place.