Actually, in a real sense, there is geographic separation: rural/semi-rural vs the de facto city-states.
Maybe the solution is for the largest cities to exist as semi-independent city-states. The citizens there cannot vote in state or federal elections, but they can have their own constitution and vote themselves all the dictators they like.
Such cities would be one-party states run by rich oligarchs, basically like now. They could do almost any progressive thing they wanted, short of executing political prisoners. Instead, they could exile their dissidents (we would thus get a stream of their best people). Meanwhile the worst people on our side would leave to get the free recreational drugs or whatever the Socialists promise. We could trade with the city-states and even have a common currency.
This is probably the greatest truth.
In Maryland, Bawlmer is a lawless cesspool where gangs of thugs loot and riot for giggles, but they never venture beyond their asphalt jungle.
*Maybe*, someday, they’d creep out into the closest suburbs but I can bet money they will never come out here to The Wastelands.
Every hick here is armed and we still have the Celtic mentality of hiding in the mountains and ridges and simply picking outlanders off.
When the Beltway snipers were headed this way, *everyone* was looking and waiting for them.
There was a collective groan of frustrated disappointment when they didn’t make it past South Mountain.
It’s genetic.
This is wrong headed thinking. Think like the founders, think little 'r' republic, think states. Breaking the USA up into 4 or 5 independent countries with a mutual defense treaty is the way to go. Or internecine bloody civil war. I am good either way.