The righteousness some feel they can interpret from Christianity is imo stronger in America than anywhere else on earth ... I found an excellent book by an Aussie author in a 2nd hand book shop on my last holiday which discusses this ... I'll try and find where Mrs Dex has hidden it (or cure my domestic blindness) and post the reference here later.
The book is American Journeys by Don Watson ... it is a worthy read and offers through observation a plausible explanation of what has driven and still drives Americans ... religion has been and still is one of the strongest drivers ... not in a good or bad or even indifferent way, but in a way that makes sense when you read it.
Cheers Dex
PS ... it was on the shelf under a coffee table (where I last left it lol)