Does American Democracy Require Christianity?

In a recent essay, “Tocqueville’s America and Ours,” University of St. Thomas Law Professor Robert Delahunty asks whether Christianity has served its purpose as a foundational political theory in America and may now be discarded:

I do not know the answer and I do not mean to overstate the risk. One must acknowledge the evidence that democracy can survive without Christian—-or, indeed, any—-metaphysical foundations. Consider the cases of Sweden and Denmark, two Scandinavian countries in which liberal democracy appears to be in good health, but which are among the most radically de-christianized nations in the West. The sociologist Paul Zuckerman spent fourteen months in the two countries, interviewing hundreds of Swedes and Danes. He found in each country “a markedly irreligious society that was, above all, moral, stable, humane and deeply good.” Although most of his interviewees denied the traditional teachings of Christianity, they nonetheless were not anti-religious, demurred at being called atheists, preferred to be called Christians, and had undergone ceremonial rites such as baptism and church marriage. But their inherited or cultural Christianity did not go deep. One Danish pastor told Zuckerman that “In Denmark, the word ‘God’ is one of the most embarrassing words you can say.” Another man recounted that a colleague who confessed, after a few drinks, to believing in God, then begged him not to consider him “a bad person.” Overall, Zuckerman found that Denmark and Sweden were societies in which most people did not fear death or give thought to the meaning of life. Yet by and large the people he encountered were happy, led productive lives, and behaved morally and humanely.

It may well be, then, that American democracy could survive in the face of radical de-christianization, such as has happened in Denmark and Sweden. It may be our democracy is not in need of “foundations,” or that a vestigial, undoctrinal Christianity can provide whatever foundations were needed. D.H. Lawrence perhaps got it right in his poem  Tortoise Shell  (1921):

The Cross, the Cross
Goes deeper in than we know,
Deeper into life;
Right into the marrow
And through the bone.

Perhaps Christianity has served its world-historical purposes and can safely depart the scene, leaving behind a society deeply and lastingly permeated with its precepts about humanity.

But one may doubt this, no?