The 3 states of the west coast can easily exit the US (Pacxit?) - maybe take Nevada with them, just to have a party zone (or annex Las Vegas & Reno and leave the rest to rot, as if it hasn't already). Maybe annex Baja California while they're at it.

Main issues would be 1) Colorado River rights & 2) whether goods being shipped to the rest of the US would be subject to extortionary rates, 2) conditions for trucking/flights into the US sector, or whether California in particuliar could give up much of their heartland market.

Northeast can consider much the same thing (NExit). Or could have a joint exit similar to Pakistan/Bangladesh's in 1947.

The Midwest states will eventually figure out that their decisive advantage of being on these huge bodies of water isn't quite such the advantage in the non-trapping post-refrigeration era when that legacy 100 year auto industry is no longer the vanguard of progress and factories can be set up most anywhere, while those big fields of corn and wheat and what-not are now filed under "commodity products". I know it's the job of government to figure that out for them even as they rail against the intrusion of government.

(Maybe we can set up some independent city-states around the Great Lakes like Chicago, Detroit & Cleveland, something like the old Hansa Baltic agreement or the free ports/special zones like Gibraltar, Melilla, Ceuta, Tangier. They can debark at Niagara Falls - perhaps get Elon Musk to set up a hyperloop transport connection)