A deepening standoff between national Republicans and top party leaders in Florida has the potential to blow up the 2012 presidential primary calendar — and do lasting damage to the GOP in the nation’s largest swing state. At issue is the early date of Florida’s presidential primary election, currently set for Jan. 31, 2012. As of right now, it’s the first primary scheduled. That’s in blatant violation of Republican and Democratic National Committee rules, which say only four states — Iowa, New Hampshire, South Carolina and Nevada – can hold primary elections before the beginning of March. But despite the...