Chuck Todd compared Gingrich holding out for Dixie (which was debunked by National Journal a couple of days ago, BTW) to Hillary waiting for March last cycle. If you lose most, or in Gingrich's case, all of February, then your fundraising dries up and the inevitability argument solidifies into granite. Apart from Georgia, Oklahoma and Tennessee, where is Gingrich going to win until Alabama and Mississippi vote on March 13? Is he really going to stay in (or more accurately, will Adelson let him stay in) with 14 losses before Super Tuesday?
Uh... Clinton held out until March and then won Texas and Ohio anyway.
