I don't think we are on the verge of a civil war even if the actual violence now and threat of localized but intense violence later this year is too high for me.
I think the violence and unrest America experienced in the late 1960s and early 1970s was worse than today's violence and unrest. Which makes sense because the causes of today's unrest is amazingly smaller than what triggered the earlier wave. And back then civilian authorities with limited military support managed it.
Today, even if communist Antifa and their allies masquerading as popular movements decide to go to war if Trump wins reelection, I think civilian authorities can do the job of defeating the revolutionaries.
Since 9/11, police are more effective at intelligence and internal policing. There are also more federal law enforcement personnel, especially when you consider the Department of Homeland Security. So committing active Army and Marine combat units is unlikely to be necessary.
Of course, a major difference is that there are cities that seem to side with the communists. I don't think the last round had that. But I don't know if this virtue-signalling support of most of those local government leftists will survive an actual urban insurgency that threatens them, too.
Violence is bad enough. But civil war seems highly unlikely.
UPDATE: This researcher doesn't think post-election insurrection is likely:
While I think some concern is valid, it is important to remember that there is a big difference between using a call to arms to mobilize your voters and instill fear in the other party’s supporters, and staging a post-election insurrection, which could subject its instigators to charges of sedition, if not high treason.
Ultimately, the three factors discussed here suggest that fears of widespread violence by vigilantes and activists during and after Election Day should be treated as fears, not as a probable outcome.
I think he is right. Violence may likely be greater than after 2016, but it will be no threat to the country as a whole.
And maybe we will get lucky and our summer of riots and arson will have slaked the thirst for street violence among the non-core revolutionaries out there.