How fitting, then, that so many of the USA's capital city buildings boast heavily Roman-inspired architecture.

What structure of USA will collapse in your estimation? Since we're talking about a democratic federation and not an "empire".

Red-blue split, roughly. Our federal bureaucracy has become a legislature with no accountability. In that regard we are a late stage empire.

Most states are not clearly red or blue. Most all of the big cities are blue, most of the countryside is red. Even texas is not 65% conservative on voting; less than 5% shift and it would be a tossup or democratic. Maybe a few states like wyoming would go clearly one way but a vast amount of states would not be able to all go one way (think of california). So the outcome of a real us split would be chaos, terror, mixed states.

I'm in a very blue state, but the rural population (30% maybe) is a different world of wealth, education, politics, population density. We subsidize their economy by building infrastructure there they can't afford (like roads and bridges). This causes endless arguing at the state level. I think a lot of the states are like this with varying % in the two groups.

First it's slow, and then suddenly it's all at once. We're still in the slow phase, for the time being.

How many SPY puts are you holding?

Puts aren't a good way to hedge against this because in the event the US empire does collapse, your US dollars won't be of much use. In fact, I'd bet that the stock market will actually shoot up to insane levels because the government response will be more money printing to fund military endeavors.

Probably better to invest in land in places with a (relatively) stable climate, good fresh water supply, and far enough north and high enough in elevation to be protected from the most obvious effects of climate change.