The whole "disband the US!" has been heard before.
Basically, they want to cut it into the Mid-west, the SW states being black, the East Coast, the West Coast.
For the most part the E&W Coasts think they'll keep getting cheap food, power, and water from the Mid-West while preventing it from getting any manufacturing by ensuring Texas doesn't side with the Mid-West to prevent the Mid-West from getting ports. Part of SoCal might or might not go to Mexico. Western Montana, North Idaho, Eastern WA into one big state/territory, Oregon and NorCal becoming another section.
It'd be pretty amusing to watch them try to decide who gets what, who has to provide what free of charge or cheaply. CA loves to go on with "SELF SUFFICIENT WORLDS FIFTH LARGEST ECONOMY!" shit while ignoring they get power and water from other states. And of course, they'd just divide the US military into equal shares.
Supposedly all the blacks would migrate to the SE states, Mexico would land-claim New Mexico, Nevada, Arizona, SoCal.
Then, of course, you have the Native Americans wanting their cut.
The most interesting thing I've seen is that they seem to think all of the infrastructure just magically stays tended to and maintained.
I'd love to see them try it, that's when it comes down to rocking the Civil War thing.