Which would also destroy the economy in the “red” areas.
Historically, when this happens (China, Spain, etc), the rural areas often win. However, it is at such a cost that “winning” often means “breaking everything”.
Make no mistake, the fanatics on the left would be content with the USA turned into a wasteland. With that in mind, the outcome of a civil war may hinge on which side has the ‘nuclear briefcase’. In other words, which side represents the government and which side adopts the position of revolutionary when the war breaks out. The left would use any method at its disposal to defeat the right. Notice I didn’t say ‘to win’, but to ‘defeat the right’. This means using poison, mass killings, even going nuclear. Much easier to do when you don’t consider you enemy to be human...