I hate to be a Debbie Downer for all of us rooting for chaos in the Republican primary, but I think this baby's over. Santorum managed a great, come-from-behind victory (or near victory, not sure yet) in Iowa, but this was little more than the last gasp of opposition before Romney overwhelms the rest of the field.
Why is that?
The problem with Santorum -- electorally speaking, I mean -- is that he has no stamina for a prolonged fight. Sure, he managed to make something of himself in Iowa, but he could only manage it by focusing pretty much all of his very meager resources there. He has almost no presence in the other 49 states, and a statewide campaign apparatus is not the kind of thing you can just whip up overnight, not even if you get a massive windfall after the initial victory. It's possible that Perry could have waged a longer campaign, or perhaps even Ron Paul, but none of the other guys ever really got their fundraising off the ground back when it really mattered.
Santorum's only real shot here is if this anti-Romney Tea-Party-cum-Christian-Right thingamajig that presumably carried him in Iowa coalesces into a full-blown opposition faction within, I dunno, the next two weeks or so and decides on its own to mobilize for him. Frankly, I just don't see it.
The far more likely outcome is that the Republican establishment gets just spooked enough to jump off the fence and line up behind Romney so as to put the kibosh on all this friendly fire. It appears it's already happening, in fact, as news broke this evening that John McCain plans to travel to New Hampshire tomorrow to endorse Mittens. I expect an avalanche of those over the next week or two as Mitt easily carries NH, brushes off South Carolina as an outlier and uses Super Tuesday as a giant victory lap.