Agreed. While it's often hard to distinguish Santorum's genuine beliefs from his pandering to the redneck vote, the distinction is somewhat irrelevant. He now stands for that base, and he needs it as a bargaining chip in pretty much any outcome that can occur between now and the convention. At a brokered convention, he'll be able to cash in that voting base for a cabinet or advisory position (probably not a vice presidential slot, but at least something) on Romney's ticket. If Romney ends up beating him outright before the convention, then he'll cash it in for a lucrative talkshow deal, a la Mike Huckabee. At the very least, and certainly in any event, he'll be able to sell a mountain of books.

The point is, from a game-theoretical standpoint, there is no benefit to Santorum in backing down from his rhetoric at this juncture. He's in an especially lucrative position because Romney is so perfectly ill-positioned to win over the base Santorum has carved out for himself. (In the eyes of the evangelical, white, working-class base, Romney is every bit the "snob" that Obama is).