The conclusion is dubious: religion as "indispensible" to the upholding of the Republican (as in, Republicanism, not the party, for the partisans) ideal? Sounds like just another repetition of the old caveat "Protestant Ethics (of America)", which doesn't hold much water to me at all.

The only truly large "benefit" that might possibly comes out of the domination of this religious ideal in the public life of Americans (often confused with the American Dream in general, which I disagree) is an informal code of ethics for public servants. Considering the behaviors of Presidents/Judges/Congressmen/every other public servants out there throughout the history of the United States, I doubt it contributes that much. Moreover, it is entirely possible to develop a separate tradition of ethics by secular means.

Quite frankly, having seen first-hand, and subject first-hand, to the lack of separation between a religion and a state -- albeit a very mild and tolerant one -- I don't like the idea. While all I "suffered" (if it is even that) were things like kneeling in prayer or studying religions that I did not really believe in, and that such things were mere annoyances equal to all other annoyances of school life, I'd imagine that a truly convinced believer of another religion would be utterly offended to pray -- or for his or her children to pray -- to the deity he or she does not worship -- an inevitability of the joining of the Church and the State.

I don't even want to go to areas when the ties are so deep the state becomes a theocracy. A theocracy is everything but the modern Western Democracy.

Truth be told, no atheists ever win high-profile elections in America. Jesus is still every President's personal savior.