The best-case scenario for Mr. Huntsman might be if you had a result like this one in Iowa:

1. Newt Gingrich — 25 percent
2. Ron Paul — 22 percent
3. Michele Bachmann — 16 percent
4. Rick Perry — 14 percent
5. Mitt Romney — 14 percent
6. Rick Santorum — 9 percent

These numbers aren’t totally arbitrary; they’re pretty much what you get if you take the current polling averages in Iowa but subtract a few points from Mr. Gingrich and Mr. Romney (and reallocate them to the other candidates) on the theory that a negative campaign might harm them both. A result like this — a fourth or fifth-place finish — would do a lot of damage to Mr. Romney. On the other hand, while Mr. Gingrich would win, it would be by an underwhelming margin amid high expectations. It would probably not reverse Mr. Gingrich’s momentum, but might constrain it to the point that he would not run away with the race. Meanwhile, Mr. Huntsman would not mind that Ron Paul had done relatively well in Iowa, since Mr. Paul also polls relatively well in New Hampshire and could complicate both Mr. Gingrich’s and Mr. Romney’s paths to victory there.

Even absent this specific scenario, there are other permutations where Mr. Romney loses New Hampshire but the candidate who beats him does not have a lock on the nomination.