There's been a lot of buzz over Des Moines Register columnist David Yepsen's crusade against the possibility of campaigns organizing non-Iowa resident college students to caucus. Most of the talk has been about whether Obama will pull in loads of Illinois college kids. But Yepsen offers another scenario, too:

On the Republican side, GOP officials are watching precincts in Council Bluffs and Davenport to make certain people aren't driving across the state line to participate. They are particularly concerned about Ron Paul's over-caffeinated backers.

This will be fun to watch--not because Paul has a real shot at winning Iowa (he doesn't), but because of the pain he can inflict on other candidates. For instance: Right now Fred Thompson currently has a good shot at placing third in Iowa. Rudy Giuliani and John McCain aren't campaigning hard there, while Fred is now throwing everything he's got into the state--to the exclusion of New Hampshire) between now and the caucuses.

A decent third-place showing probably keeps Fred alive and kicking into New Hampshire--especially if Romney loses badly to Huckabee, rebooting the GOP race and giving everyone new hope. But if Thompson loses to Ron Paul? Then consider Fred dead. 

--Michael Crowley