Some good points here. A civil war could easily turn into total chaos, even by the usual standards of war. Modern America is split into many factions, more complicated than the left vs right spectrum often depicted. Many people identify with particular races, religions, and political ideologies that could turn into temporary alliances. Many who identify as "leftists" are pro-government but others are part of anti-establishment far left groups. Some who identify as anarchists are far left, but others are more right-libertarian. It's similar with conservatives. The worst case scenario is that America devolves into tribal warfare, like a dystopian movie like Mad Max. The most likely "solution" would be some kind of powerful fascist government that could restore order.