Speculations on the future of American religion in a post-United States:
The fragmented, multipolar political landscape of future America will tend over time towards something like a feudal or tribal condition. As above, so below—polytheistic paganism will appeal in this cultural habitat in a way that it doesn’t under a more centralized and hierarchical social regime.
Also contributing to the nascent pagan revival will be a general counter-trend toward more ancestral beliefs and ways of life, a kind of neo-romantic primitivism that emerges in response to our rarefied technological environment. Rather than furthering our alienation from nature, many will employ technology to deepen and strengthen our connection to it—for example, through enhanced human-animal communication, the development of new senses which allow us to “feel” ecological variables, cognitive enhancement of select animal species, and the aforementioned use of biotechnology to acquire animal phenotypes.
Tribes (city-states, fiefdoms, kingdoms, ethnic groups) will revive old gods (Norse, Greco-Roman, Egyptian) and raise new gods to represent and (literally) embody their polity and its local natural environment.