Well you're right in a way because even demons believe in Jesus' power but being a Christian is much more than just believing you have to live the belief and thats what we all struggle to live up to this everyday. Bush is self righteous he thinks those who don't think like him are wrong and so as many other Americans who now think being republican is being Bush-like. The guy has messed up but again I still believe he's Christian.
I don't think saying someone is not Christian is a condemnation unless you think of being a Christian an exultant position (which many believe). To me being Christian is not to put yourself above others rather to meet them as they are. I mean that the values George Bush seeks to live, the form of Christianity he professes, are not what I think of as being Christian. i don't think it is enough to say, even feel you are saved, to be a Christian. It is the attempt (which we will all most assuredly fail at) to live the values expressed in the teachings and life of the Christ. Putting yourself in His hands, being saved, seems to be used as a way of legitimating copping out on the really hard work of, not just being a Christian, but being a good and whole person in all its meanings.