And you assume these states that will supposedly secede are monolithic. That’s fantasy. Even in the states you mentioned, there are divisions. This isn’t 1860. The stark divisions that existed then (geographic, cultural, economic) are long gone. There will never be a civil war 2 in America like the last one. Instead, it would be house to house, street to street.
So is the USA monolithic?
You didn't read my post, I said and agreed there would be some internecine fighting/unrest the seceding state(s) just like in the first civil war in both North and South. But that, IMO, would NOT be the main event or significant in any meaningful way.