Bush Derangement Syndrome
I might not have been a fan of George W Bush, nor of legacy rule -- but I wasn't against him either. I did vote for him, because Al Gore was such a douchey little ignoramus and hypocrite (later Kerry was even worse). But I had some reservations, and I was far less a war hawk than he was. To me, he turned out to be quite a bit better than I expected. And almost everything the Press and their followers whined about, was blown way, way out of proportion. Especially the deeper one looked.
So I'm fine with people disliking Bush or some of his moves. But if they start saying something like, "Bush lied, people died", pretending Saddam was a saint, that this was the first unprovoked war, or that Bush was responsible for 9/11, or the Real-Estate Bubble, I know I'm dealing with a BDS sufferer. They might be geniuses in other aspects of their lives, but if they start ranting about that stuff, they're like a special needs kid talking to Einstein about religion: absolutely no value can be gained through engagement.