Sho-Con: The divisions were always there, but what turned it from mild tension to the food fight it is now was Ron Paul's candidacy in 2008, the overzealous way his supporters went about supporting him (“Revolution!”), and the ugliness it brought out in the “establishment” in their (over)reaction to the Paul supporters. It became “us” and “them.” If you nodded and smiled, or were the least polite or civil to a Paul supporter, you were austracized as a “Paulie.” If you leaned toward Paul, even if it was just because he wasn't John McCain, but were seen fraternizing with long-time Republicans, you were called a “RINO.” If, like me, you weren't either (though I did support Paul in 2008 — mainly because ANY candidate would have been better than McCain), you were (and are) treated like crap by BOTH camps. And so it remains. Like a rock chip in a windshield, the cracks will just keep spreading.
DFO: I agree with McGruber that this is one dang good explanation re: split in Kootenai County GOP.