The concept of “pan-secessionism” that I have promoted on this website/blog for 20 years is now entering the mainstream, with 1/3 of the US population now expressing at least casual sympathy for secession by their particular geographical region or state (up from 1/4 only 7 years ago as the charts below indicate).
https://attackthesystem.com/2021/07/23/pan-secessionism-is-now-a-mainstream-idea/
If more than 50% of military and police support secession and more than 50% of armed & trained civilians support secession then if the opposing side realizes they would lose & surrenders it can be accomplished peacefully, if they do not surrender then defensive force can be used to accomplish it and the side supporting secession would win
If less than half of all the listed groups support secession then it would most likely fail and a lot of people would die if they attempted it