Looking for a book analyzing the downfall of American culture since leaving its Christian roots?

I heard about this book from one of my parents, and can't seem to find it anywhere. The book is by a Muslim author who analyzed the decay of America and its moral values since moving away from its Christian roots. I just heard about the book in the last 7 or 8 months, so I believe it is fairly new.Looking for a book analyzing the downfall of American culture since leaving its Christian roots?
I don't know, but since America's founding fathers were deist, not Christian, I can't imagine such a book would be particularly accurate.