What about Atheist country?

[Ryantology]

First thing I thought!

It is pretty evident that America's ostentatious piety comes from a relatively small (and loud) minority of professed believers. The majority of such people would probably sleep in on Sundays. Most of them already do.

The Pew survey making headlines because of the unexpected rise in non-affiliation pegs the number of professed affiliated at around 83%, but no more than half this number actually attends services (this not accounting for the strong possibility that many people probably lie about doing so).

In other words, if there would not be a backlash against the atheism part of this scenario, one would reasonably expect little practical difference for most Americans.