> This doesn't explain. It would be easy enough to change the Constitution to
establish a religion, which, if Americans were religious in the same sense as the populations of the Islamic states, they would surely do. Religion must function differently here.
Look at the history of religion via politics. Religion is one of the leading sources of social criticism in the US - because it allows for a "higher law" that serves as a trump card against popular sovereignty. If the state were back by religious authorities... ("a higher law") then the critique of religion would be a more attractive resource (which would include the internal critique of religion as well). Religion is appealing because of the disenchanting effects of modernity.
We might also want to think about the science / religion debate which is, in many respects, quite unique to the US. Many (most?) religious traditions have not had an antagonistic relation to science, yet, for Christianity, it was largely through science that the critique of religion was first accomplished. So, in the "west" religion and science became polarized. So, in an advanced technological society, the critique of technological colonization finds it best ally in the existing religious traditions... (like the critique of capitalism in liberation theology or the critique of genetic manipulation from, say, the moral majority).
> I'm going to suggest that it's largely a species of entertainment, a
participatory, vernacular art form. Additionally, in the case of fundamentalism it might offer lower-class traditionalists and nostalgics relief from bourgeois cultural pressures and continuous modernization. It asks mostly to be decor; hence the uncomprehending offense taken when even vague, pro-forma religious expressions are kicked out of school, even from the important sentimental apparatus of football games and graduations.
Religion is also a nice way to foreclose on dialogue. If one is in possession of the truth, there is no reason to talk about it further. People that aren't much interested in the antagonisms of complex decision making, especially when these antagonisms aren't conducive to their interests, might find religion a comfortable way to end a conversation.
Religion is a way of coming to terms with something that is lacking, a foundational flaw in the human character. It provides comfort and consolation for contradictory politics by smoothing over the edges and gaps. But this "totality" of a worldview itself is lacking, since it cannot fill the gaps completely, which is why fundamentalisms emerge. The more religion puts up the pretence of having the answers, the more likely it is to develop in a hardened form, evermore exclusive. Rainer Nagele has some interesting thoughts about this (not with regards to religion, but with regards to consensus): the attempt to be universally inclusive (ie. the attempt to bring all human beings together) is a radically exclusivist politics; universal inclusion stems from the fear of being exluded, which makes inclusivism evermore exclusive.