Ramesh Ponnuru writes here that Giuliani is down but not out:
His polls may have dropped, but I think he's in better shape to win the nomination than he was when the polls were better for him. The best chance to beat him was for one other candidate to win a bunch of early states before the Jan. 29 and Feb. 5 primaries, where he is doing very well. His support might fall in those states if a strong candidate emerges from those earlier primaries. But a mixed result in those early states - say two or three different candidates win in them - will leave his support in the later states intact.
At the moment Giuliani's problem is that he's on defense. To stay strong heading into Florida on January 29, Giuliani needs to go back on offense. It may be time to dust off his "12 Commitments", which seem to have been gathering dust over the last few months.