The other thing is that there's a track to the nomination for anyone who comes out a clear second to Romney in early primary states. If Iowa and New Hampshire winnow down the candidates to where it's Romney versus any one other Republican, the large number of Republicans who find Romney unacceptable can be united. It's not only important for Romney that he win Iowa -- it's important that it come out being something like 30-20-20 in his favor rather than 30-25-15. In the first scenario, there's no clear person for later-state Romney haters to align behind. In the second scenario, there is.
One of the things that made the war in Libya so interesting from a purely military-strategy viewpoint was how different the two sides were. Gadhafi had a conventional army with lots of tanks and trained soldiers. The Free Libyan forces had a ragtag band of dudes with small arms backed up by awesome NATO airpower. It was interesting to see who would win, with the two forces so differently configured. If Gingrich, or really any Republican other than Perry, is at a major national polling advantage over Romney when the Iowa caucuses come around, Iowa and New Hampshire are going to be interesting in much the same way.