Well, we did have a civil war some time ago! But given the gross imbalance of military capability between the state and the citizen, I’m not worried today about a successful violent overthrow of the USA.
That was equally true in Yugoslavia, and indeed in Afghanistan. I think it's extremely naive to assume the US is immune from this. When I told people 10-15 years ago that I thought the US was ripe for and vulnerable to autocratic political leadership nobody took it seriously either, yet here we are.
