Judith Warner has a good piece on The New York Times site about the meeting between Bush and the Queen:
Bush talks with his mouth full because he can. He drinks mineral water straight from the bottle at a formal function because he doesn’t have to prove his good breeding to anyone.... The idea that being boorish, ill-mannered and uncouth somehow brands you as a “regular guy” holds water only if you ascribe to the view that the people, globally, are idiots. It works, I suppose, if your whole political reason for being is to dress up elitism in know-nothing populist garb.
Remember Bush's father campaigning in 1988 and how he espoused his love for country music and pork rinds? Bush II did grow-up in Texas, but he has many generations of bluebloods preceding him.