Okay, so Rick Santorum's getting out the race, lest he look like a big loser in his home state of Pennsylvania. It's amazing he stayed in this long. I guess one should not underestimate the feelings of Republicans who don't like Mitt Romney and/or moderates and will vote for anyone else.
This may be mind-reading from afar but I've long had the feeling that neither Santorum nor Gingrich thought they had a shot at the nomination when they got into the race; that each, having been out of politics, thought it would be a good way to renew their names with right-wing voters in order to reap other rewards — speaking fees, book sales, maybe a show on Fox News. I think they got in the way Pat Buchanan used to get in…as a means of personal promotion. This could also be said of some others. Could Herman Cain really have believed he had a good shot at being the Republican nominee? Could Trump?
I further speculate that Rick and Newt each had a largely-delusional moment when they turned to their spouses or someone and said, "Hey, you know I could really win this!" They have since come crashing down to reality…but both have probably achieved their original goals.