“Why attack Santorum?” asked Jamal Simmons, a Democratic strategist. “Santorum is doing what no Republican has really been able to do so far, which is provide Mitt Romney with a real contest with voters.”

Democrats are also hoping that Gingrich follows through on his caucus-night suggestion to “tell the truth” about Romney even if it means being negative. Romney could find himself being double-teamed at a pair of debates before New Hampshire’s primary on Tuesday — Gingrich has shown that he’s a fan of Santorum and will probably be saving most of his criticism for the front-runner…

One key difference is that whereas Obama and Clinton were stepping toward more centrist views to win over white moderates, Romney is competing for conservative votes on the wing of his party, opening him up to taking positions that could make him vulnerable as the nominee.

That’s where the other candidates come in, the way Democrats see it this time around.