| Every President has been Christian. The biggest anomaly was JFK who many thought would hand over the White House to the Pope.
Even though there is a seperation of powers, the original intent was to uphold the equity of Christian denominations over another. The Mormons who weren't considered a legitimate Christian sect were driven out of state by the US Army and was grudgingly accepted once they prospered in Utah. So all of the original intents and mindet for freedom of religion was with a Christian eye.
Various legislation are enacted with the morals in principles of Christianity. Pornography and censorship is one. The Second Great Awakening provided Prohibition. Manifest Destiny was justification for an unprovoked war with Mexico.
Today, I believe the nation is still Christian minded even if its influence has waned for whatever reasons. While it's social climate is always evolving, there are still many signs out there.
Never underestimate the power of stupid people in large groups |