We have no government armed with power capable of contending with human passions unbridled by morality and religion. Avarice, ambition, revenge, or gallantry, would break the strongest cords of our Constitution as a whale goes through a net. Our Constitution was made only for a moral and religious people. It is wholly inadequate to the government of any other.
John Adams from Letter to the officers of the first brigade of the third division of the militia of Massachusetts, 11 October 1798, in The Works of John Adams, Second President of the United States with a Life of the Author, Notes and Illustration, by his Grandson Charles Francis Adams, vol. 9 (Boston, MA Little, Brown and Company, 1856- as quoted by Charles Murray in American Exceptionalism.
The Founders created a very unique government that was centered around a very unique population. Crossing broad oceans and developing virgin hostile territories required a certain character of self-reliance and industriousness that may have had as much to do with our founding documents as the study and the minds of our founding fathers.
Modern immigrants still seek the freedom and opportunity found in few other places on the planet but the wide social safety net may undermine other characteristics that were important to our early development. Elitist social tinkering and economic central planning are both failing in their objectives and erasing the classless society that defined our early years.
Without virgin territories and the physical safety barriers of the oceans, easily overcome with a zealot with a box knife, we are left to consider if the personal characteristics that made America unique and great will survive as a dominant political force.