Paul Rosenberg predicted this in Breaking Dawn (2016).
https://www.amazon.com/Breaking-Dawn-Paul-Rosenberg/dp/09…
Think of it as Mandibles, but from the perspective of 1) people who have fled (or are fleeing) the major cities; and 2) the ruling elites.
A caveat about the third part of the book: I found it interesting, but disappointing in terms of the plot. It is likely to annoy both atheists and Christians (in particular, but not exclusively).