It is a mystery. The people I talk to love Newt and when I ask if they are going to vote for him, they respond that they have heard that he can’t beat Obama, so they don’t want to waste their vote.
Ding! Ding! There is a group of people that keep shifting from candidate to candidate based upon who is perceived as most likely to beat Obama. They just switched back to Romney, or the group that finds him (or Satan) acceptable. Santorum may not fall as far as predicted as many of these gave up on Newt. If Santorum does really well tomorrow, he might even get them back.