Unless you were a voter from one of the jurisidictions involved, last night’s Primary Watch was pretty underwhelming. Santorum didn’t get his upset win in Wisconsin. But the early exit polls there turned out to exaggerate Romney’s margin of victory, which led to a lot of ultimately erronous commentary about how Mitt had finally won evangelicals and “very conservative” voters in a seriously contested state. So it was not the crushing defeat for Rick it initially looked like, and the Death Watch surrounding his campaign will have to continue at least until April 24, when a loss in Pennsylvania would be very difficult for him to rationalize.
In terms of how non-Republicans interpet these late primaries, I think it’s important not to read any sort of ideological meaning into them, such as a rejection of Santorum’s “extremism.” In Wisconsin, only 28% of primary voters said Santorum was “too conservative,” barely more than the 23% who said he’s “not conservative enough” (which, of course, remains the main argument in Team Romney’s anti-Santorum propaganda). The fault lines in the GOP that have been evident throughout the primaries have only faded slightly; there’s no immediate reason to think that if Rick can hang on until May, he won’t still do well in states where a sizable majority of primary voters are conservative evangelicals. There just aren’t enough such states left to save him now.