By now, everyone knows that Mitt Romney’s inner circle was righteously peeved at New Jersey Gov. Chris Christie for spending the final days of the 2012 presidential race arm-in-arm with President Obama as they toured the Jersey coastline after its thrashing by Hurricane Sandy. The buddy-buddy act boxed Romney out of national media coverage for days while lending the president some bipartisan street cred. But it wasn’t just the storm. Christie had rankled Romney’s team throughout the campaign: He held back his endorsement as long as possible, flirted with big-shot GOP donors who begged him to jump into the race...