Newt Gingrich’s presidential campaign has an interesting response to a call from the super PAC supporting Rick Santorum for the former House speaker to exit the race. It’s front-runner Mitt Romney who should say sayonara, says Gingrich policy adviser Vince Haley, Politico reports. The pro-Santorum Red, White and Blue Fund put out a statement Wednesday urging Gingrich to stand aside, so that the former Pennsylvania senator can stand as the former Massachusetts governor’s sole conservative challenger. Haley, appearing on Geraldo Rivera’s radio program, would have none of it. But his first response was to take on Romney rather than Santorum....