Splitting peacefully is in everyone’s interest
Some people (Tim Pool for example) have predicted a civil war in the US. I don't think that will happen. I think it is much more likely that people will vote with their feet and separate into two distinct cultures, akin to cell division. A lot of the early-movers have alreay moved.
Consider this situation: https://twitter.com/elonmusk/status/1700297475628871719
Due to this law, right-wing late-movers who really don't want to leave California are now rather forced to leave or else they will lose their children.
The US will split. I hope it splits peacefully.
Discussion
Yes. There is also a legal mechanism. State governments can secede from the union.