Chris Christie — He has successfully governed as a Republican in blue New Jersey. He would normally be a top tier contender, but his problem can be summed up in two words: Jeb Bush. There is room for one million insurgent candidates, gadflies and niche candidates. Christie is the GOP establishment, and the establishment only has room for one candidate. Once Jeb signaled that he was running, Paul Ryan and Mitt Romney saw the handwriting on the wall and bowed out. The Bush family network and the Karl Rove political machine will be solidly behind Jeb. If Jeb by some shocker decides not to run, then Chris Christie is very plausible. However, if Jeb were to get out, Romney would probably get back in. That would again give Christie a problem, although perhaps slightly less so. Christie will get attacked by the left for being a Republican, from the right for being too moderate, and from the establishment that wants Jeb. He’ll be crowded out with no place to go.