They’re ain’t no such animal that permits states to say, ptui I spit and leave. We fought a Civil War over it.
A lot of rights are reserved to the states and to local government. Of course some militia wackos interpret local as “me”, but to continue…
Over that is a netting of federal control. At least in theory that’s the stuff that applies to ALL Americans, no matter what state they live in, e.g. civil rights, environmental protection, supporting the interstate highway system, post office and military, etc. Since each state has its own government, the application of some of this stuff gets, shall we say, creative. And Washington is fond of making majesterial decisions and leaving paying up to the local yokels. This is what makes politics fun.
But splitting the union? Nah. I appreciate your example (Bigtenia?! grin!) but in fact the carnage of the Civil War ended slavery and in Shelby Foote’s words, made us a “we”. For good or ill, we have a clear centralized government in the way that Canada, for example, does not. (No value judgement, Canadians: observation!)
So secession is not a constitutional option, on the state or local level. We did that, and have a lot of dead to show for it. As far as “Bigtenia” seceeding, the viability issue is too complex to guess, militarily and diplomatically speaking. In a historical sense, they’d probably be some of the last to consider secession, anyway. Check out Civil War battlefields; Ohio, Michigan, Indiana all lost a lot of people to hold the union together.
But extrapolating your point, what about states in the southwest seceeding? After all, they were just plain swiped from Mexico to begin with, so there are some real historical and cultural reasons…
(intellectual speculation is not treason!)