Charleston, South Carolina (CNN) - With Newt Gingrich creeping up in the polls and potentially on the cusp of a South Carolina victory, one of Mitt Romney's senior advisers sought to change expectations ahead of Saturdays' pivotal presidential primary. Though his campaign has competed aggressively in the state and is hungry for a win here, Romney strategist Stuart Stevens said the idea of a loss to Gingrich on Saturday is not far-fetched. "Do I think we could lose South Carolina? Sure. Of course," Stevens told CNN after Thursday's presidential debate in Charleston. "The very idea that we are sting where...