This is an interesting primary in terms of how to spin it afterwards. The latest polls suggest a huge Romney win, something on the order of 15%. If Santorum could make it somewhat close, he could spin it as a moral victory, which would then carry him into the Louisiana primary on Saturday, where he would be expected to win. If Romney has a blow-out win, on the other hand, that would solidify his narrative of inevitability. Which is pretty strong anyway. The scenario for Santorum remains: make it close in Illinois; win Louisiana; win Wisconsin on April 3rd. Then see where we are.
Weirdly, the Wisconsin primary (where the Regular Family lives) may turn out to be the Last Stand for non-Romneys. Buckle up.