Sabato's Crystal Ball analyzes the next week of races:
Our guesstimate of Romney’s delegate edge — 49 over Santorum — comes almost entirely from Virginia. Subtract out Virginia, and Super Tuesday becomes essentially a draw. Obviously, Romney will do very well in Massachusetts, where he served as governor, and in neighboring Vermont — both of which are Democratic states whose Republicans aren’t particularly religious or conservative compared with other states. Ohio, which will be the key state in Super Tuesday press coverage and which we project Romney will win quite narrowly, is in almost any event likely to be relatively even in delegates, much like Michigan was.
Harry Enten calculates that the delegate allocation rules in the states voting next Tuesday will give Romney a major delegate bump. My view is that if Romney loses Ohio to Santorum, whatever the delegate result, he's a zombie nominee.