GETTYSBURG, Pa. (AP) -- Bowing to the inevitable, Rick Santorum quit the presidential campaign Tuesday, clearing the way for Mitt Romney to claim the Republican nomination.Santorum, appearing with his wife and children in his home state of Pennsylvania, told supporters the race for him was over, but the fight to defeat President Barack Obama would go on.He pointedly made no mention or endorsement of Romney, whom Santorum had derided as an unworthy standard-bearer for the GOP. The former Pennsylvania senator stressed that he'd taken his campaign farther than anyone expected.\We will continue to go out and fight and defeat President Barack Obama