According to Richard John Neuhaus, here’s how the public square “became naked,” and why it doesn’t stay that way:
The political theory and practice of the Western world is the story of a growing Erastianism in which the modern state, brooking no competition from other claims to sovereignty, has attempted to eliminate the “boundary disputes” between temporal and spiritual authorities. The United States in its founding, as is evident in the Religion Clause of the First Amendment, is the great exception to this general pattern. But “American exceptionalism,” also on this score, needs constantly to be reexamined and, when necessary, defended. Without that, the state drives out prophetic religion and establishes a monopoly on public space and public meanings. That is the circumstance referred to as “the naked public square.” Which, as we must never tire of recalling, does not remain naked but is taken over by the pseudo-religion established by state power.