The always provocative Stanley Hauerwas, in an essay for the Australian Broadcasting Corporation's Religion and Ethics website, argues that American Protestantism is dying in part because it conflates God and country, although not in a straightforward nationalistic sort of way:
America is the great experiment in Protestant social thought, but the society Protestants created now threatens to make Protestantism unintelligible to itself. Put as directly as I can, I believe we may be living at a time when we are watching Protestantism, at least the kind of Protestantism we have in America, come to an end. It is dying of its own success.
Protestantism became identified with the republican presumption in liberty as an end in itself. This presumption was then reinforced by an unassailable belief in the commonsense of the individual. As a result, Protestant churches in America lost the ability to maintain those disciplines that are necessary to sustain a truly free people - people who are capable of being a genuine alternative to the rest of the world.
The great irony is that the almost pathological fervency with which the religious right in America tries to sustain faith as a necessary condition for democracy is the surest formula for insuring that the faith that is sustained is not the Christian faith.
More Americans may go to church than their counterparts in Europe, but the churches to which they go do little to challenge the secular presumptions that form their lives or the lives of the churches to which they go. For the church is assumed to exist to reinforce the presumption that those that go to church have done so freely.
The church's primary function, therefore, is to legitimate and sustain the presumption that America represents what all people would want to be if they had the benefit of American education and money. That is what Americans mean by "freedom."