Two types of people need two types of country.
One negative: Secession takes a very long time.
It won’t be just saying ‘I identify as...”
Takes 5 minutes. The legislature puts it up for a vote.
I think I get your meaning. It's not like leftist John Doe across the street or Right winger Jane doe on the other side will get to stay. One will have to go to the left or right state and no others can live there other than ambassadors. Probably not even their families.
I'm thinking the left can have western WA and the northwest corner of OR. The Bay area of CA and Las Vegas. CO has been lost for a while. NM will have to determine their own fate. The rest of the west belongs to Americans (conservatives). New England and NY would go to the heathens (leftists). VA may be lost so that can be thrown in.
The military and government, minus the deep state, will remain with us Americans. Technology will be common to both countries. No leftists will be allowed to set foot in New America. They will be regulated to the crapholes they created all walled off and unwelcome in the USA. Commie Peoples Democrat America or whatever they want to call themselves will soon crash, burn, and die. After that we can re-absorb those territories as they become available.
All illegals will have a choice of going to leftist territories or back home where they belong. No exceptions. Birthright citizenship will be fixed to be what it should be now. One parent must be an American citizen for the child to be an American. The commie PDA might choose to leave the way it is. Their biz.
If it's decided to maintain an illusion of a common country; all leftist states will become territories and lose all state rights. They will have no senators or representatives in congress. There will be no commie democrat party.