'The Flag and the Cross': Defining Christian Nationalism

How pervasive is Christian nationalism in the United States? Before answering, a more pressing question is: What is it? Here the people paid to define our terms are all over the place. Christian nationalism can involve a national church like the Church of Scotland. It can be a form of civil religion, as in "one nation under God." It can also dissolve into American exceptionalism: "a city set on a hill." Whatever the definition, attaching national or civic meaning to divine purpose is as old as recorded history.