That's the title of an article by Prof. Angelo Codevilla, whom we've met in these pages several times before. I've learned to respect his views very highly, because they've proven prescient over a long period. Here's an excerpt.
It all starts with getting people accustomed to hating each other. And that starts at the top.
Saying hateful things about one’s opponents is a time-tested way of stoking supporters’ enthusiasm, of building support for one’s own side. But when blood is spilled, someone, then everyone else, tends to use it as a pretext for inciting more violence. That’s the meaning of blood-feud.
. . .
Police in leftist jurisdictions have stood aside as violent groups disrupted the 2016 Republican presidential campaign and the 2017 presidential inauguration in Washington, D.C., as racial mobs have ravaged malls and shut down major roads, as conservatives have been attacked physically as they tried to speak or merely observed. The media have basically justified the violence. The other side has done nothing comparable—yet.
. . .
What should happen, what can happen, when the real, existing violent organizations of the Left—Antifa and the several radical black organizations—try to exclude or to punish? Several cities—Portland, Oregon and Charlottesville, Virginia among them—have had their streets taken over. What happens when these organizations organize mobs to harass their least favorite people? What happens when some of them wind up dead?
At a certain point, the other side shoots back. Here as elsewhere, the several police forces may be expected to split and take opposite sides. Then the army’s special forces become the arbiters, and the war rages.
We know that our ruling class having largely made government into a partisan thing, America has crossed the threshold of revolution. While we have no way of knowing what lies ahead, we know that the spiral of political violence has already taken its first fateful turns, and that the logic of our partisan ruling class is pushing for more.
There's more at the link. Highly recommended reading.
I think - I fear - Prof. Codevilla is exactly right. I have friends who live in or near cities dominated by far-left-wing politics and movements (e.g. Portland, Oregon). They all complain about feeling like foreigners in their own cities, ignored by local government, taxed more and more to pay for programs with which they utterly disagree, and generally vilified as being part of the problem because they won't "get with the program". A number of them are looking to move away. Some already have.
That applies to travel, too. A number of my friends will no longer go to certain cities at all, because crime, homelessness, panhandling, etc. is out of control, they fear for their safety, and they're not allowed to carry a firearm for personal protection. I don't blame them. For the same reasons, I won't go to those cities, either. I suspect places like that are losing a fair amount of business and tourist revenue from such unofficial boycotts; but it doesn't look like they care about that at all, provided they can keep to their politically correct, moonbattish ways.
To me, one of the most dangerous aspects of this sort of politics is the attempt to criminalize people by passing laws that liberals know will not be obeyed. For example, consider bans on certain types of weapons and/or accessories, enacted in states like New York and Connecticut. It's been estimated that compliance with the new, highly restrictive laws is extremely low. That's civil disobedience to an astonishing extent. It's made criminals - according to the letter of the law - of those who've refused to obey the new rules. What will happen if attempts are made to identify them, confiscate their non-conforming weapons, and charge them with an offense? Will they go quietly? Or will they decide that resistance is the better part of valor? If they do, they probably outnumber the law enforcement officers and agencies that will be arrayed against them. If I were among those officers, I'd be rather hesitant to push things too far. Indeed, some senior officers have said precisely that, to the discomfort of their politician bosses.
I suspect Prof. Codevilla is right on the money, yet again.