|This is the third of a series of posts that explore the danger that the United States' hyper-polarized political environment might suddenly erupt into large-scale political violence. Links to the full series plus other escalation-related materials can be found on the Conflict Fundamentals Seminar/Blog page on Escalation.|
As bad as things are in the United States, there are, unfortunately, a lot of ways in which things could go from bad to worse. For example, if large numbers of people lose faith in the ability and willingness of law enforcement to protect them from criminal activity, they are more likely to feel a need to arm themselves. This, combined with a fear that new gun-control legislation might make it impossible to purchase guns in the future, explains the many surges in gun purchases that have followed mass shootings. Especially troubling is the fact that the current (Spring/Summer 2020) surge in gun purchases (which is the largest thus far) is occurring at a time when there is little talk of new gun-control legislation.
We have reached the point where any sort of violent incident poses a substantially increased risk of runaway escalation—especially, if perpetrators aren't promptly arrested and responsibility clearly established. Under current circumstances, most everyone is likely to blame the other side for any violent incidents that occur. (Even if your side seems guilty, you can always blame provocateurs who, in today's politics, might actually be responsible.) There is also a danger that someone (who may well have psychological problems) will feel compelled to take the law into their own hands in ways that create another provocative incident.
While we may well be able to weather occasional provocations like this, the risk will rise dramatically if we start to see a flurry of incidents in which law enforcement is seen as acting in biased or ineffective ways. This is especially likely to happen when perpetrators and motives are unclear and self-serving narratives emerge within various factions asserting that they have been wronged and the system has failed in its responsibility to protect them. This, again, increases the risk of "vigilante" justice. For example, when communities believe that they are victims of hate crimes and that the police are not really trying to pursue the perpetrators of those crimes, then they may take it upon themselves to retaliate against those they believe responsible.
The risk of such incidents obviously goes way up when you have clandestine provocateurs trying to push
The hoaxes, outlandish in their details, have spurred fringe groups of conspiracy-minded Americans to action by playing on partisan fears. They have led to highly combustible situations — attracting heavily armed militia members and far-right activists eager to protect values they think are under siege — as well as large mobilizations of police. 
In other cases advocates may be genuinely trying to push a more major confrontation, because they think that their side can handily win a decisive victory. This brings to mind the picnickers who went to see the first battle of Bull Run, thinking that they would be witnessing a quick, easy, and decisive victory in the then-just-beginning U.S. Civil War. Instead, they had to run for their lives as they witnessed the beginning of what would be a four-year horror from which the nation has, 150 years later, yet to be able to recover. 
Even more worrying is the prospect that more ruthless and sophisticated provocateurs might try to destabilize the United States by pushing violent confrontations as part of some new hybrid warfare strategy.
Now think about what might happen if we experience a genuinely major act of violence, say an Oklahoma City-style bombing, a Kent State-style shooting of protesters by ill-trained National Guard units called in to help restore order, or the kind of political assassination (or attempted assassination) that we saw in the 1960s, 70s, and 1980's with John Kennedy, Malcolm X, Martin Luther King, Robert Kennedy, George Wallace, and Ronald Reagan.
Again, responsible political leadership of the kind Robert Kennedy demonstrated following the assassination of Martin Luther King might enable us to weather the storm. However, if you have prominent political leaders who interpret such events as a call to arms, then things could get bad fast.
We are likely to pass through this initial initiating chain of events quite quickly. After that, escalation is likely to be become an explosive positive-feedback system which quickly produces a rapidly-growing list of unrightable wrongs that will solidify feelings of hatred, fear, and a desire for vengeance. This could produce the kind of large-scale civil unrest we saw with the 1960s race riots  or the Vietnam Protests. 
This time, however, the violence might not be confined to Black neighborhoods, college towns, and major city centers. Warring factions could easily start attacking one another in their home communities. At this point, the way in which police and military forces respond will be critical. If they move to enforce the rule of law based on long-established legal principles then things might be contained. If, however, these forces were to enter the fray as competing heavily-armed combatants then we are going to be in real trouble.
Unlike the US Civil War, the divorce / succession solution is not really going to be viable. Our populations are too geographically intermixed. In other words, war, if it breaks out, is going to be very, very ugly. Let's not make the mistake of thinking something as horrific as Syria can't happen here. Now, not later, is the time to step back from the brink.
 Phillip B. Levine and Robin McKnight, " Three million more guns: The Spring 2020 spike in firearm sales" Brookings. Monday, July 13, 2020" https://www.brookings.edu/blog/up-front/2020/07/13/three-million-more-guns-the-spring-2020-spike-in-firearm-sales/
 Shawn Boburg and Dalton Bennett. "The Trill: A fake flag burning at Gettysburg was only is latest hoax." The Washington Post, July 17.2020. https://www.washingtonpost.com/investigations/2020/07/17/gettysburg-antifa-flag-burning-troll/
 Elizabeth Nix. "The Worth Picnic in History Was Interrupted by a War." The History Channel. Aug. 30, 2018 https://www.history.com/news/worst-picnic-in-history-was-interrupted-by-war.
 Ofer Fridman. Russian 'Hybrid Warfare': Resurgence and Politicisation.Book Review by Robert Legvold, Jan/Feb. 2019. Foreign Affairs. https://www.foreignaffairs.com/reviews/capsule-review/2018-12-11/russian-hybrid-warfare-resurgence-and-politicisation
 "Robert F. Kennedy's speech on the assassination of Martin Luther King Jr." From Wikipedia https://en.wikipedia.org/wiki/Robert_F._Kennedy%27s_speech_on_the_assassination_of_Martin_Luther_King_Jr.
 Virginia Postrel. "The Consequences of the 1960's Race Riots Come into View" The New York Times. Dec. 30, 2004. https://www.nytimes.com/2004/12/30/business/the-consequences-of-the-1960s-race-riots-come-into-view.html.
 "Lists of protests against the Vietnam War." in Wikipedia. https://en.wikipedia.org/wiki/List_of_protests_against_the_Vietnam_War