Totally agree. I think the break up would occur building Republics of like minded people. Moral/Political = Morapol. Raiding parties would go to each coast to take what they want and return to their Morapol.
The breakup would not be decided by proximity IMHO.
I’d like to live just long enough to vote in one election in which the choice was between republicans and libertarians, and democrats were not involved.