Bachmann and Pawlenty was at least, to some degree, wearing on both of them. Bachmann got the better of it, but those jabs about her failure to actually succeed at anything certainly left a mark, and her victory wasn't THAT overwhelming.
Paul vs Santorum, meanwhile, was basically a rout. Santorum threw out a wild accusation that Paul has addressed hundreds of times before, which Paul shot out of the sky, then he threw another attack at Paul to which he was easily beaten again but then attacked himself (accused of backing the Iraq war, which isn't going to make you many fans), then he threw a snide jab at Paul when he figured he could get away with it if it was vague.
Its like the difference between two very different fights. The first is long, lasts several rounds, and goes to the already stronger fighter by TKO, but narrowly. The second is a series of the first guy charging the second wildly, getting punched in the face and knocked to the ground, then standing up and trying it again before being KO'd.
Ha ha ha! Thats rich.
Mr.Santorum (polling 1-5%, going nowhere) really shouldn't degrade himself to debating with Mr.Paul (polling 14% and rising) since Mr.Paul has no chance.
I suppose Karger shouldn't have to degrade himself to debate with Bachmann, either?