What is the fallout from Thompson's entry? Well, if he lasts more than a few months, he effectively blocks former House Speaker Newt Gingrich from entering the race. His presence makes Iowa, South Carolina and Florida more problematic for former New York City Mayor Rudy Giuliani, providing Thompson finishes either first or second in any of the states.
Thompson eliminates any momentum former Arkansas Gov. Mike Huckabee might have been gaining among conservatives. And he creates just another roadblock for former Massachusetts Gov. Mitt Romney as he enters the more solid red states.
The ultimate issue for Thompson will be the candidate himself. He is likeable, sane and articulate. But his public speeches during his "pre-announcement" stage have been, well, totally uninspiring. He seemed to lack a coherent message and a will to truly fight.
The question now is whether Fred Thompson is the type of actor who is only good reading a script, or if he can pull from his gut the sort of emotion needed to win. If he has the latter talent, he might just be the dark horse of the decade, for not only the Republican Party but for the nation. If he doesn't, he will likely die a quick political death. That would leave only one potential "would-be" candidate -- Gingrich. And he has never been accused of lacking fire in the belly.