Next Tuesday’s contest in Florida is crucial for McCain. Giuliani has bet everything on Florida and if McCain can beat him there—the two are currently level-pegging in the polls in the sunshine state--he pretty much knocks him out of the contest and can expect to sweep up the lion’s share of Giuliani votes: both candidates appeal to hawkish Republicans who want strong leaders. This would send McCain into February 5th, where 21 states vote, with the wind at his back which he’ll need given Mitt Romney’s financial and organisational strength.
The other question is if the Republican establishment will row in behind McCain. Parts of the conservative base and elite have an almost irrational dislike of McCain and some validation would be helpful to him. Mel Martinez, the Florida Senator who is a close political ally of the Bush family, is expected to endorse McCain on Monday and there is talk that others will soon follow.