Tomorrow is the big day in Ames, the Iowa GOP straw poll. No actual delegates will be awarded, but the candidates will be working hard to bring their supporters to the event and win over uncommitted Republican activists through a strong showing. Some things to look out for:

1) Mitt Romney is heavily favored to win, thanks to his strong Iowa organization. In factt, his three main rivals — Rudy Giuliani, John McCain and Fred Thompson — aren't even contesting the the event as a result of his seemingly inevitable victory. But in a way, this means he has to really win. A small plurality would give an appearance of weakness. And if he were to actually lose, he would be in serious trouble.

2) Assuming Romney comes in first place, who comes in second and below? Mike Huckabee and Sam Brownback have been competing for the same Christian right base vote, so whoever loses that particular two-man race within the race will be in big trouble. And if Ron Paul does poorly, it could give us a hint that his Internet-driven campaign can't actually deliver real supporters to vote for him. Will the nativism of Tom Tancredo and Duncan Hunter have any attraction?

3) How many people will actually vote for Giuliani, McCain and Thompson. They have no organizations actively bringing people to Ames, so it can't be that many. But if enough people show up on their own and get their candidate to surpass participating candidates, it would definitely benefit them — and force some others out the door. Which leads us to...

4) Wil any candidates do so poorly that they have to drop out? Mike Huckabee has already said he'll have to drop out if he doesn't do well — and the Club For Growth has responded with an attack against him going into the caucus. If Sam Brownback does top him, it could be the end. Tommy Thompson seems like another obvious choice, as well.

5) News updates can be found at IowaPolitics.com, the Des Moines Register's Politics section, to name two good local sources. Plus there are some right-wing blogs that are sure to hard at work: Iowa Presidential Watch and Iowa Voice, among others.