DAYTON, Ohio (AP) - Rick Santorum is taking another swipe at Mitt Romney's big-spending campaign, saying that the election must be earned, and not "bought."

He and Romney have been campaigning in Ohio ahead of tomorrow's ten Super Tuesday contests. The primary in the Buckeye State is the one that is hardest-fought.

Santorum told supporters in Dayton to "look into what the candidates have overcome and what they offer to this country -- not just what money they have." He's casting himself as a scrappy blue-collar fighter, saying someone who grew up "having to fight for everything you got" is "exactly the kind of person that we need to have."

Romney today has again been highlighting his business background, as he tries to focus attention on economic issues. He told supporters that other candidates have "debated about the economy" -- but that he himself has "actually been in it."

Romney heads into Super Tuesday having won four consecutive contests, including Saturday's Washington caucuses.