No I can't tell you one either and obviously the Roman Empire is the most striking example of what happens next.
I have no idea whether we are heading for Diocletian or Romulus Augustus. The latter I suspect, the former I fear in several of the likely Demrat nominees.
McVey
I think the Roman Empire, even when it was falling, was much smarter than we are. At least they actively fought the Barbarians (accomodating them when they absolutely had to). In contrast, we invite them in and declare that we need them to prosper.