We had a separatist movement, it was called the Civil War, and did not end well for the separatists. US states do not have any legal mechanism to exit the union

We had a separatist movement, it was called the Civil War, and did not end well for the separatists. US states do not have any legal mechanism to exit the union, although Texas claims it has that right. We do have a lot of nut jobs, particularly in low population rural states like Idaho, and they have ideas. One idea is to split off parts of California and Oregon into the state of Jefferson. Another was to split California into 6 states. All of these schemes just happen to give conservatives more power in the Senate, and are unlikely to ever happen.