1. I think it is a huge deal for Santorum. My sense is that a large plurality of potential Republican voters would prefer to vote for Santorum, but also don’t want to vote for a bumbler or sure loser. This group doesn’t want to vote Romney, but they’ll do it if they think Romney is their only prayer of beating Obama. This means they are going to be looking to see how Santorum handles himself when the spotlight is on and his rivals are focused on taking him down.
2. Romney can’t win a positive victory. It doesn’t matter what policy he comes out for. Who is going to believe that Romney really believes anything he says? The best that he can hope for is that right-leaning voters will think that:
a) he is a smart guy with executive competence and that counts for a lot
b) he is the only electable candidate on the stage
c) Santorum the earmarking deficit ceiling-raiser isn’t that much more authentic than Romney(good luck with that one.)
d) maybe Romney will not only sell out to conservatives to get their votes, but he’ll also stay bought after the election (I’m not sure how much conservatives are willing to delude themselves about this.)
3. Gingrich just has to hope that, with the other candidates attacking each other, his outlandish combination of promises (huge tax cuts! no Medicare changes for anybody who doesn’t want them! private accounts for Social Security! cheap gas! moon colonies! - actually I don’t think he’ll mention the last one) and attacks on Obama will get him the love back. Maybe conservatives have seen through his act for good. I hope so.
4. Watch Ron Paul. He is set up to be Romney’s attack dog during the debate.