Good showings on Tuesday, Santorum aides believe, will allow Santorum to use the coming three weeks without a Republican primary or caucus — Feb. 7 to 28 — to beef up his campaign and finally emerge as the one-on-one rival to Romney…

Romney, with his carpetbombing negative ads, is the chief offender in that — after losing in Nevada, Gingrich asked, “If the only way Romney wins is suppressing turnout, how’s he going to do that in the fall?” But Gingrich’s angry reactions have given Republicans a picture of their two leading candidates as whiners and bullies — certainly not an image the party wants to carry into the general election.

That’s where Santorum comes in. Back in Iowa, voters turned to Santorum after first exhausting other possibilities; when they looked around, they realized he had been there all along. Recently he’s been plugging along in the expectation that Gingrich will self-destruct, and then a Santorum moment will come again.