A couple of generations ago, it wasn't uncommon for a person to be born, live, and die without going more than 50 miles from their home; seeing someone from out of state was a novelty. And it wasn't that far a stretch to move from "stranger" to "enemy" when controversial policies were in play.
I think this is over-stated.
I'm a pretty good example of the ever-moving American: I have moved states 10 times in my lifetime, with some intra-state moves, too.
Most folk aren't like me. There are whole swaths of folks who never move from the state of their birth.
For instance, much of hte inner-city black underclass doesn't even travel outside their metro area, let alone make interstate trips. Back when the choice was migrate or starve, many moved North. Nowadays, "starve" has been taken off the plate.
Many rural whites are similar, but for family reasons.
I've read bios of some authors who, like Isaac Asimov, rarely ever left the island of Manhattan! Talk about provincial!
OTOH, it is true that many of these folks have no real affinity to their state.
But it seems to me, almost on every issue, there are people in every state on either side. It wouldn't be not so much Texas vs. California, as people from certain classes and political stripes against people of the opposing faction in the same geographical area, a horrible chain of acction, retaliation, counter-retaliation.
I think this is closer to the mark and the effect of any civil war.
I'm going to treat this as a political thread and move it, as I expect it'll likely turn into a discussion about reasoning why such an event could occur.
Remember to keep it civil.
Advocacy of treasonous or illegal actions will be cause for punitive actions.
Oh, so you're going to make a pre-emptive strike? Do you happen to be a native of South Carolina? How well did that work out last time?
[Fort Sumter]
Moreover, I, as a native Michigander, have no reason to take up arms against another state--well, except maybe Illinois. If it would help, I might take up arms to protect the Great Lakes from being laid open to destructive invasive species. However, I don't think that there is any really effective way to do that and war would only increase our vulnerability.
You'd likely have an ally in Florida. I couldn't swing a dead cat without hitting a transplanted Michigander when I lived down there.