After the fall of the US government, I plan on selling pieces of fallen sky to Elvis and the rest of the aliens.
Hopefully lighthearted sarcasm is still allowed in this thread.
Seriously, I cannot imagine the US being in any danger of ceasing to exist in my lifetime. I can foresee a period of basic rights being severely curtailed, but I think that would be a short-term problem that would be very dramatic but most certainly nonviolent.
Tyler's view of history has three problems. First of all, it's written from the perspective of a monarchist. Second, he's talking about a democracy, not a republic. Athens was a democracy, not a republic. The people of Athens voted on bills directly themselves. Finally, his theory is pretty much disproven by the examples of China, which acheived greatness without any notion of "liberty" in the 1400's, and France, which was the predominate land power in Europe from 1500 to c.1875 while going through 3 revolutions.