Rudy may still win and McCain may get a bronze...that would cause problems.
And it isn't inconceivable to think, considering the fluidity of McCain's supporters, that a loss in Florida could be a real killer to the McSurge we've seen. Many of McCain's supporters are supporting him because of their hatred of Romney and Huckabee, as I know I would in the earlier states to knock off Huckabee/Romney. If Giuliani can win Florida and prove he is still a viable candidate, and his strategy is working as planned, then McCain could lose a lot of support. McCain is hated much more by the base than Giuliani is. I know many who would refuse to vote for McCain. I'm sure Rudy would have the same, but McCain has always had people among the base that have opposed him.