I see it much differently.
In my view, Santorum surged because there were many people who are not comfortable with the potential for Bad Newt to show up at any time.
Santorum has the advantage of being not Romney AND not Gingrich.
If he understands that, he’ll stick to his own path. That way he’ll pick up the Bachmann and Perry voters as well as the voters who were never all that comfortable supporting Gingrich.
Santorum never got the tens of millions viciously spent against him by the Romney people in Iowa.. that simple