Are we a Christian Nation? Obama vs. McCain

Obama's view:  "We do not consider ourselves a Christian Nation.  We consider ourselves a nation of citizens ... with ideals and principles" ... but I guess I don't know where those ideals and principles come from because I didn't grow up in America and my tele-prompter isn't telling me.

John McCain:  “I would probably have to say yes, that the Constitution established the United States of America as a Christian nation. But I say that in the broadest sense. The lady that holds her lamp beside the golden door doesn’t say, ‘I only welcome Christians.’ We welcome the poor, the tired, the huddled masses. But when they come here they know that they are in a nation founded on Christian principles.”