SPARTANBURG, S.C. – Newt Gingrich, gaining in the polls, retreated Saturday from a line of attack that he’s been using more frequently against frontrunner Mitt Romney. Asked at a debate here to reassert his critique that Romney was merely a “manager” and incapable of changing Washington, Gingrich flatly declined to do so. “No,” the former speaker told moderator Major Garrett of National Journal after Garrett asked him to apply the critique to foreign policy.