Jonathan Chait of New York magazine writes:
It is not that Republicans won’t vote for Romney. It’s that Romney does not capture their fundamental attitude toward Obama. He can adopt the positions of the base, but he can’t seem to ape their feeling of fear and outrage toward the current president. Gingrich may lack money and organization, but he has a real opportunity, and Romney surely knows it.
There’s something to this analysis, both in terms of Gingrich’s chances to win the nomination (which are quite real) and what his appeal is (and what Romney’s appeal is not).