You are deep in an intractable blue tribe information bubble, and it's badly affecting your analysis. Skipping past the numerous factual errors in the article, these are the most likely civil war scenarios:
1) Trump wins
20 US cities decide to emulate Portland, Antifa organizes, Federal authorities start actually using the power they've already been granted to ship C-130 loads of LARPers to Guantanamo and everyone supports this so their towns don't burn down.
This in practice will be close to "The Troubles" in Ireland.
2) Biden Wins
2a) The wider left thinks the riots will stop if Biden wins, because they're not rioting about Black Lives at all, they're rioting about Trump. But that's not what BLM and Antifa are rioting about, and both of those organizations hate Biden too, and also hate Kamala. And since we have 200 officer involved shootings of black people per year in the USA, and since the new cultural acceptance is that we riot even when use of force is justified, Biden has to deal with a riot in December and has no plan to react in any way differently than Trump reacted. With Kamala on point, the reaction is probably much more vicious than Trump, and then the failure mode is exactly like (1) above.
2b) If Biden wins, it's completely reasonable to project that some QAnon wacko will take that as an indication that a globalist pedo deep state conspiracy has reasserted control over the government, and that the only possible recourse is to shoot up a Democrat Baseball Practice in the same way a deeply indoctrinated Bernie Bro did back around the midterms. If this happens to Biden/Kamala, they will dive headlong into nationwide AR-15 confiscation, and then you get the REAL worst outcome, because the nationwide reaction to that will be the immediate pivot to Sanctuary Districts against the law, in the same way as happened in Virginia in 2019. And Biden can't use the Army to enforce the law because (A) the Army is literally too small to enforce it, and (B) the Army are all AR-15 owners.