There is nothing wrong with that. Just make smaller countries and each city can act as a country and run its own affairs and interact with the other partners. If 18 states can agree with each other, then they can band together. Populous states can do likewise and each can have its own constitution and rules. The populous city states can manufacture the equipment, cars and trucks and the rural population can buy from them and sell them back food and energy in return! They can each pay their own taxes to govern themselves, pay for their own healthcare systems and whatever pension plans and government infrastructure they might want to have in place.
If the will of the people is going to want to change the constitution - so be it. However this has to be negotiated so that all parties agree. A good starting place is what is there already - the constitution under which the states co-exist already. It had worked well for hundreds of years and all states had flourished. As the Republic has evolved, there seems to be a bigger divide between urban and rural lifestyles and the country may need to divide itself up to keep each part distinct and happy. You might need to have an EC formed with a common currency and cultural difference recognized.
The major issue comes in equality of wages and taxation. New York has high taxes, high cost of living and therefore high wages. That is same in most big cities and their corresponding states. That does not equate to the rural. Currently high taxation is causing large companies to flee the city or country and develop in cheaper less costly locations. The reality is this is why large American corporations are global. They manufacture goods in China using cheap labor and then sell products at home and transfer the money back out to Tax havens where they pay less tax. Some of the smaller ones are just moving to states where tax laws are more favorable.
Just make smaller countries Why? By one man one vote it doesn't matter how big the country is.
If 18 states can agree with each other, then they can band together. Let's get something straight; just because some Republican officials from 18 states joined in a law suit doesn't automatically mean that the population of all those states have agreed to anything. There isn't a single state that is 100% Republican, which means that in all those states there are also Democrats.
If the will of the people is going to want to change the constitution - so be it. However this has to be negotiated so that all parties agree. It will never happen. Breaking up the country in two parts? No way, you will never get the population to go along with that. And look what happened in Germany after the war, when they forcefully broke up the country in two parts. It was the will of the people that ultimately brought them back together again.
A good starting place is what is there already - the constitution under which the states co-exist already. Exactly, the country is not called the United States of America for nothing. It's already a union of reasonably independent states.
But all this, just because the guy you like lost the election? Really?