Less than two months ago, Herman Cain, who was out of the race for the Republican presidential nomination, stood on a stage in West Palm Beach, just three days before the Florida primary and told the crowd, “I hereby officially and enthusiastically endorse Newt Gingrich for the president of the Unites States.” Gingrich had just come off a sweeping win in South Carolina, had the fundraising dollars pouring in and a financial safety net in billionaire donor Sheldon Adelson. But on Monday Cain walked back his endorsement of Gingrich saying, “With all due respect, let’s get on with this, OK?”...