By pretty much any accepted definition we are a Christian nation. Given that we have a state religion and over 70% of the nation define themselves as Christian. You can't decide what constitutes "practicing".
That was my point regarding "Christian values", it's a meaningless phrase, so how can you attest we don't have them? It's most sensible definition though, would be those espoused by Christ, which as a nation, for the most part, we do hold.
Regards "actually reading the bible" I'll wager I know it better than the vast majority of people, and I'll actually be curious as to what parts of it you think are immoral that are also intended to be a moral code for Christians. James' epistle and Paul's letters will refute pretty much any you care to mention between them, with the exception of promiscuity, which I think is fine but they deny - that said, most people disagree with me on that, too.
I'd love to see links to them debating more moderate Christians other than the odd Dawkins appearance on the likes of Sunday Morning Live and similar. The problem in these seldom appearances though, is that they still make a point of arguing the same lines, which are generally irrelevant (Hitchens was less guilty, he did tend to be better at tackling the specifics of the people with whom he was conversing, but he was often still at fault). For instance, in almost any argument against faith they'll bring up Creation being incompatible with science (which is acknowledged by every major church, never applied to Islam, was abandoned by Jews in the Middle Ages and was never intended to be a literal story in the first place), the binding of Isaac (a story of sacrifice from oral tradition, absolutely not ever meant to have been an example to anyone or of morality) and things like Jonah and the Whale (a satirical story) as proof of the Bible's nonsensicalness.
I'm happy to see them debate relevant stuff, the Intelligence Squared debate with Fry and Hitchens was excellent for example, since it presented such a specific remit, but all too often they drop to tropes which simply don't apply to the majority of religious people outside a few small independent churches and the Bible Belt. It's often embarrassing to watch, and really, really disappointing as an atheist with great respect for the people's academia.