It's hard to compare to a full implosion like Harris who magically seems to never run out of time, energy or material to continue imploding.
What I'll say about Santorum is that he is a person who generates a very strong antipathy just being who he is -- I live in PA and a lot of people just plain don't like the man, without any regard to issues.
I don't think how you run a campaign means much in comparison to how the candidate connects.
Santorum comes off as that kid who told everyone in high school he was going to be big shit and then set about doing it without serious regard to what the point of it in fact was.
In that respect, I'm not sold that you can build a good campaign around Santorum.
Incumbents, especially in states where their party controls the machine, just don't get the plug pulled on them like this unless they IMed a page using Jack Abramoff's cell phone while playing cards with Duke Cunningham and Bob Ney using the Ohio state employees pension fund's coin collection (did I skip a scandal?).
Compared, especially, to other Ohio GOPpers, DeWine has been downright electable. Consider folks like Blackwell, Schmidt, Ney, etc. who make the Ohio GOP look corrupt and stupid even by the GOP's strident standards.