Actually while he is dead wrong about Bush.
His perception of this particular demographic (my own happily) has some truth....the good parts..lol
If you read it carefully, you'll note that the author is not expressing his "perception" in those positive statements about the fighting Scot-Irish of America. He is quoting the thoughts of James Webb and Walter Russell Mead, then cramming their fine sentiments into his "dumb Americans" packaging.
He is trying to paint noble and brave men who fight and die for this country as moronic cannon fodder no smarter or more understanding of the reasons for the war than the horses that die beside them.