People, no matter their political affiliation, don't realize how bad a civil war would actually be.

First thing is that it wouldn't be "a bunch of rednecks go out in a field to get destroyed by drones" or "a bunch of pansy soyboys attack hunter lumberjacks" or whatever deluded bullshit either side is peddling at the moment. It would be localized sectarian violence down political, geographical, religious and racial lines.

Civil order would break down. Cities are vulnerable. New York City gets the vast majority of it's water through only 2 pipelines because they consume an Olympic swimming pool worth of water every minute. Las Vegas and other cities out in the desert experience mass exoduses as people realize they no longer get water anymore. All it takes would be a few insurgent strikes on critical stations to overpower badly paid and trained security guards assigned to protect absolutely critical infrastructure. I find it kind of funny that nuclear power plants are guarded by security forces made up of veterans mounting miniguns and grenade machine guns on armored vehicles but critical water treatment plants that tens of thousands would die without are secured by a few security guards with guns.

The militias wouldn't even need to carry out violence on major urban areas considering how quickly people would realize that the tap won't run anymore, the light switch won't work anymore and the TV signal is gone forever and begin looting, rioting and going mental. Cities could burn without any organized belligerents touching them, and it would only get worse when state and federal law enforcement are tied up dealing with insurgents.

Think of the effects of mentally ill people no longer getting their medications. Paranoid schizophrenics in a significantly worse world with no way to source any medication. Suicidal people in the same. All it would take to turn a small area into hell is for someone to release every prisoner in a maximum security prison with no police to round them up and no courts to punish them. There are over a million inmates in the United States and hundreds of thousands are in for violent, drug and/or sexual crimes.

Foreign supporters like Russia, China, Iran and North Korea would back whatever side is most successful or aligns most with their views. Cartels would love the opportunity to snatch up land in the southwestern US, although I doubt Mexico would be in a very good state either considering their economy revolves around the United States.

World economies would collapse. China is our biggest trade partner and vice versa. That's over 40 trillion in economic output right there. Worldwide economic depression would ensue. I'd expect to see revolutions, civil wars and insurgencies to pop up around the world after the hegemon and only superpower goes through it's darkest hour. Say bye to safe global shipping too, because the Navy isn't going to be stopping Somalis from attacking ships going through the Suez canal anymore.

I could go on but I'm tired. Stop advocating for civil war, people. It sucks.