Every time someone brings up civil war I bring up the fact that most gun owners in the USA barely know how to shoot a gun much less hit something. Most guns are handguns which are useless in combat. Then the fact that these lazy bastards have to get off the couch and go somewhere to possibly die. If you are in Texas that could mean over a thousand miles to the liberal west coast of Washington DC. Of course in your scenario the military will just roll over and go to the dark side. Even if the MAGA nuts take over a medium sized city like Austin or something. Biden will immediately send in the national guard from a liberal state like California. The logistics for a real civil war make it nearly impossible for a country this big.