The more I see of McCain, the more I suspect that he is, in part, the product of two things. He graduated from the Naval Academy in 1958. Before that, he attended a good prep school in northern Virginia. That means that his understanding of goverment probably owes a good deal to the consensus liberalism that was the reigning idea in the schools in the 1950s. McCain also seems to have the bull dog stubbornness and "don’t tred on me" attitude of Keltic culture. This is conjecture, but it might explain some things about him.
Update: I probably should have used the title, "McCain’s Political Character," as it would do a better job describing what I’m suggesting.