Romney to make Santorum's Democratic robocalls a key attack line

“It’s a major issue. [Santorum is] trying to pass himself off as the true conservative in the race, but he’s supporting the liberal Democrat line against Governor Romney,” said Ryan Williams, a spokesman for the Romney campaign.

He added of Santorum’s efforts to find Democratic help in the state’s open primary: “This isn’t going anywhere.”

A campaign aide said Romney may even work Santorum’s courting of Democrats into Romney’s stump speech going forward.