The cancelation of a Donald Trump rally in Chicago on Friday for fear of unrest is the low point so far in a political campaign that has been marred by violence.

It may not even be the worst of it unless the Republican candidate stops advocating brutality.

On Saturday, four Secret Service agents had to rush on stage when Trump was giving a speech in Ohio to prevent a protester reaching him.

Police in Kansas City used pepper spray on crowds outside a Trump event later that day.

The billionaire, who is leading in the polls to win the Republican Party’s presidential nomination, took to Twitter to complain that “thugs” were trying to shut him down. But he maintained at the same time that the turmoil had only “energized America.”

Ideology of violence

Ezra Klein argues at Vox that such rhetoric is more than an aside. It is the core of Trump’s ideology.

“The protesters who interrupted his rally, the political correctness that kept the police from cracking their skulls, the press that takes the hippies’ side — this is why America has stopped being great” to Trump’s mind.

What he promises to do is “toughen up” up the country and make it “win” again. If that means beating up some people who stand in his way, Trump is only too willing.

Violence is scary. But violence-as-ideology is terrifying. And that’s where Trump’s campaign has gone.

Klein’s article contains plenty of examples, from Trump asking supporters to “knock the crap out” of protesters to lamenting — yes, lamenting — that “nobody wants to hurt each other anymore.”

“There used to be consequences” to protesting, said Trump — wishfully.

Clearly, some of his supporters have taken it upon themselves to bring back the good ol’ days.

Mob rule

In a thoughtful post at Talking Points Memo, Josh Marshall writes that people are prone to do and say things in a crowd they never would on their own — and often come to regret.

For example, there was a Korean War veteran at a Tump rally in Louisville, Kentucky earlier this month who was videoed yelling at and shoving a black female protester out of the event. He later apologized, saying, “my emotions got the best of me and I was caught up in the frenzy.”

No one should be absolved of responsibility for their actions, argues Marshall. The man should obviously have known better.

But blame also goes to Trump who is deliberately creating an atmosphere that “disinhibits people who normally act within acceptable societal norms,” according to Marshall.

He is drawing in, like moths to a flame, those who most want to act out on their animosities, drives and beliefs.

Escalation

Marshall is fearful of the consequences, as he should be.

As the unrest at his events escalates, so does Trump’s rhetoric. The mogul doesn’t tone it down; he doubles down. He spreads false rumors about a protester’s sympathies for Islamists. He tells demonstrators that he will “ruin the rest of their lives” if they continue to interrupt his events. He accuses “communist” Bernie Sanders, a Democratic presidential candidate, of dispatching agitators to his rallies (another lie) and plays with the thought of asking his own goons to do the same.

“Be careful Bernie,” he tweets, “or my supporters will go to yours!”

It was only a matter of time before somebody would act on the things Trump has said.

We know where this is going. Americans had their George Wallace. The Italians had Benito Mussolini and Silvio Berlusconi. Hungary has Viktor Orbán. Venezuela has had Hugo Chávez and Nicolás Maduro. Would-be strongmen always feed off of people’s anxieties and encourage their supporters’ worst instincts. They scapegoat, they shame weakness and offer up easy solutions and “strength” to vexing problems. It never ends well.