Why are we assuming that all of the people outside of the cities suddenly flip to being leftists who love their state? In any civil war California will have one hell of an insurgency to deal with inside its own state. These things have to be dealt with before projecting power into other states. You seem to still be picturing a US civil war as being just the first one replayed, with nicely defined states, in the modern world. This won't be the case.
These are 21st century filmmakers trying to impress their worldview into a general idea of what a civil war would mean in this day and age if that wasn't obvious.
Surprise! But to those who don't know Hollywood film writers lack the ability to understand the brutality of what that type of conflict would entail and even if they did, they will cling to their ideas of what it should be over what it actually would be, like a security blanket.
Conservatives when they imagine a Civil War imagine themselves as a paragon of virtues and symbols of badassery who would never do anything wrong, who will cut down and easily defeat any city raised force of arms because they are
just better.
Meanwhile Liberals are also paragons who will easily invade the countryside and crush these ignorant and stupid redknecks with superior numbers before ushering in a golden era.
When someone writes these shows it's going to be from one standpoint or another by someone who wants to push some agenda of their respective beliefs and this always will drag these types of shows down.
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