Does Thompson have ANY chance of being a President? No.
A Vice President or cabinet officer of high rank? Yes, with McCain's help. Thompson is the sort of lackluster person who will not outshine McCain. Face it, people go to sleep listening to him talk. Thompson makes Gerald Ford look exciting!
Thompson can be a hero to McCain if he can take enough financial and electoral support from Huckabee to put Huckabee in second place all the time.
Fred Thomson the "Fix" is on! Why did he, all of a sudden, get energized in South Carolina? He had no chance of getting the 1st, 2nd or 3rd slot, but was able to peel off enough votes that McCain, one of the many liberals on the Republican side, was able to barely beat Huckabee (who is a true conservative, by the way).
The question I have for McCain is this: Do you intend to offer Fred Thompson a job should you become the party's nominee? No other explaination is plausible. Now that Thompson has flown home to Mother, maybe he can sit back and wait for his reward should McCain become the nominee.