Per William Saletan:
And referring to Kerry's claim that he voted "for the $87 billion [for postwar Iraq appropriations] before I voted against it," Giuliani jokes that Kerry needs two Americas so that in the second America, "he can vote against exactly the same thing" he voted for in the first America. The delegates roar their approval, but it's a lie. What Kerry voted for was an alternative that would have paid for the $87 billion by rolling back Bush's tax cut.