Mittens needs FL. He cannot afford to lose there and still hope to win the nomination.
Cain is very close already to 200 EVs, with lots of room to grow.
Cain if he can get VA + FL and win in SC, should be able to capture the nomination if he can stay there, but he’s still got a ways to go to catch up to Romney in the polls.
FL + SC + VA + TN + IN would put him first in states and EC votes, and Romney for the first time wouldn’t be leading in EC votes.
You are assuming that the primary states are all winner-take-all.
In 2008, most of them were -- and that's how McCain locked up the nomination without ever winning a majority in any state.
In 2012, however, many states have switched over to a proportional voting scheme -- e.g., win 25% of the vote, you get 25% of the delegates.
Under these circumstances it will be very difficult for anybody in this crowd to win a majority of the delegates before the convention.