the thing is, Newt's still in, and except for Romney, everybody else is gone. So you might want to think that through a little more.
Newt’s still in for two reasons.
The first is the same reason he pretended to be running for president in the first place, which is to get publicity and bolster his foundations, increase his speaking fees, his TV appearances, etc.
The second is he needs to try to continue raising money to pay off the $4.5 million campaign debt he has admitting to oweing....which probably means it is considerably more than that.
Pawlenty dropped out immediately after Iowa because he didn’t get the support he had hoped for and also because he agreed to back the Romney campaign in return for help in retiring his campaign debt. Newt will likely make a similar sort of deal with Romney and the RNC in exchange for their assistance on his political debts.
This is how these things go. You run, you lose and then you get in line and back the nominee.