I just realized another reason why America is not a Christian nation. My mom sent me a sermon in which the pastor talked about "honoring the king." If the colonies did just that, we wouldn't have the United States we have.
If that were the only contradiction christians could ignore...
But the ironic thing is that rebellion is the very foundation America was founded on. Even if you could somehow justify that this country was founded on Christian principles or that the Ten Commandments is relevant today, according to the Bible, we are more of a pagan nation XD (rebellion is as the sin of witchcraft)