I’m sure there are eggheads around here who’ve thought deeply about this, but it seems to me that there are two forces at work in politics: greed and anger. Greed is the default setting – the greed of the H-1b lobbyist, the greed of the La Raza chauvinist, the greed of the ordinary citizen who wants his taxes cut and services increased while raising the taxes of others and cutting their services. As Lincoln said, “It is the same spirit that says, ‘You work and toil and earn bread, and I’ll eat it.’”

When the consequences of that greed become apparent, there’s anger. And it is only by harnessing anger that political change is possible in a democracy. Martin Luther King in his “Letter from a Birmingham Jail” – responding to his correspondents’ reference to “tension,” i.e., anger – wrote: “I have earnestly opposed violent tension, but there is a type of constructive, nonviolent tension which is necessary for growth.”

We’ve got plenty of anger right now – genuinely justified, righteous anger. But anger is an incendiary emotion. Any politician who sets out to use that anger to effect political change has a special responsibility – greater than for status quo candidates – to see that the anger is used constructively, and not break out of its proper bounds. To use it as a cooking fire, as it were, and not let it break out into a forest fire.

This is where Trump and Sanders have both failed. Trump’s failure is more obvious, and more reprehensible. While Trump has often urged his supporters to restrain themselves and act responsibly, he has also, repeatedly, condoned and even encouraged violence. For instance, this from a rally in Iowa last month: “If you see somebody getting ready to throw a tomato, knock the crap out of them, would you? Seriously, OK? Just knock the hell — I promise you, I will pay for the legal fees. I promise. I promise.” There are plenty of other examples.

Sanders, the other anger candidate, has not encouraged violence, though he hasn’t been tested, either, since his gatherings haven’t been disrupted by protests – yet. But given the Left’s dominant role in political violence and intimidation over the past several decades, Sanders’ response has been weak. Under ordinary circumstances, it would be adequate for him to say, as he did, that “a candidate for president of the United States should condemn violence not encourage violence.”

But his are not ordinary circumstances. It’s no coincidence that the leftist storm troopers who shut down Trump’s Chicago rally over the weekend (and who clashed violently with police) are Sanders supporters; their totalitarian desire to prevent Trump from speaking is the flip side of their support for Sanders. That’s why MSNBC crowed, “How Bernie Sanders supporters shut down a Donald Trump rally in Chicago”.

That means Sanders has a responsibility not only to mouth platitudes, but to forcefully state that he rejects – disavows, even – the support of anyone trying to shut down Trump’s political gatherings.

There should be no need to remind conservatives that the Sanders supporters disrupting Trump rallies really are our contemporary counterpart of the Sturmabteilung, as Heather Mac Donald spells out on the homepage today. The Chicago protests by Sanders’ supporters “were not,” in the words of NR’s editorial yesterday, “oriented toward political expression but toward its suppression.” The Left’s Brownshirt units, organized by Moveon.org and funded by George Soros, are in no way equivalent to a 75-year-old Trump supporter punching someone in the nose.

Before we relive the political violence of the 1960s, or worse, both of the Anger Candidates need to engage in what King called “self-purification.” The specific context of King’s efforts was different, of course; workshops to ensure that participants in civil disobedience could resist the urge to strike back when attacked.

But the imperative is the same: any political actor in a democracy seeking to harness public anger for constructive ends must purge himself of the desire lash out, and make unmistakably clear to his followers that he expects the same of them. Only in this way might we avoid what Madison saw as the fate of democracies, which “have in general been as short in their lives as they have been violent in their deaths.”