This "fight" over what separation of Church and State means has been ongoing since before the very beginning. Jefferson's Virginia Statute for Religious Freedom (https://en.wikipedia.org/wiki/Virginia_Statute_for_Religious...) was actually quite controversial, even long after it was (barely) adopted by the Virginia legislature.
The fight has never been about the political and religious history; it's been about the meaning and implication of that history. Does the fact that Christianity played such an important historical role in European and American political history mean that it should therefore be given special legal status? For example, is it therefore okay for the government to display the 10 Commandments but refuse to display Buddhists' 5 Precepts? Where do you draw the line between historical homage and preferential treatment? Can such a line even be drawn? The anecdotes and contours of the debate have changed over the centuries but not the fundamental conflicts and tensions.
The fight has never been about the political and religious history; it's been about the meaning and implication of that history. Does the fact that Christianity played such an important historical role in European and American political history mean that it should therefore be given special legal status? For example, is it therefore okay for the government to display the 10 Commandments but refuse to display Buddhists' 5 Precepts? Where do you draw the line between historical homage and preferential treatment? Can such a line even be drawn? The anecdotes and contours of the debate have changed over the centuries but not the fundamental conflicts and tensions.