A father and son wait to order at a Texas barbecue joint. (Photo ©Chris Wilkins/Texas BBQ Posse) It's hard to say what's a more emotional subject for Texans, barbecue or politics. Over the years we've tried to keep the Posse blog free of partisan politics, there are plenty of other places on the web where you can endlessly argue that subject. But when it comes the BBQ, strong loyalties and opinions have been shared between writers and readers on the Posse blog over the past five years. Nothing gets BBQ fanatics going like a list of the "top" BBQ joints…