As I Understand It (Scripture Study)
Matthew 13:33 (NIRV) 33 Jesus told them still another story. "The kingdom of heaven is like yeast," he said. "A woman mixed it into a large amount of flour. The yeast worked its way all through the dough."
As this is the case, the Word of God over powers any element of which it is a part.
If the Word of God is introduced into any element, it will expand and take over. So no corrupt and sinful society can credibly claim to be Christian.
So, is America a Christian nation?
We can only answer that question individually, for ourselves.
And it is not the aggregate that determines whether we are or aren't.
Some breads weigh more than others. Some are simply more important. It is just about impossible to judge for the nation. It is difficult to weigh ourselves.
Maintaining our standing in Christ takes diligence.