The barbs are personal, the differences are multiplying among Republicans, a party divided over spending, foreign policy, a willingness to risk a government shutdown in order to defund the health care law and more. “I didn't start this one and I don’t plan on starting things by criticizing other Republicans,” Sen. Rand Paul of Kentucky said recently as he and New Jersey Gov. Chris Christie likened one another to various cuts of a butchered pig. “But if they want to make me the target, they will get it back in spades.” …