I logged onto Twitter on Saturday night to find a message from Alan Dershowitz. “The both sides argument is always proper,” he tweeted. “Blaming only one side— the “other” side— is too easy. The shoe on the other foot test requires that you condemn your side’s bigots along with their side’s.”

“Shootings at places of worship, targeting of lawmakers playing baseball, & mailing pipe bombs all are dangerous symptoms of a deep underlying sickness in our system,” he went on. “But the root causes include a growing intolerance on both sides of the political spectrum.”

Shootings at places of worship, targeting of lawmakers playing baseball, & mailing pipe bombs all are dangerous symptoms of a deep underlying sickness in our system. But the root causes include a growing intolerance on both sides of the political spectrumhttps://t.co/C6VcEev0KM— Alan Dershowitz (@AlanDersh) October 30, 2018

It’s a familiar sentiment. Credentialed centrists often blame both sides for the incivility that marks American politics today. It made me think of Av HaRachimim

A few hours before reading Dershowitz, I had been reading the prayer in shul. (Av HaRachimim isn’t usually read on the Shabbat before a new month, but because of Pittsburgh, our synagogue made an exception). Written in the late 11th century after crusaders on their way to Jerusalem massacred Jews living near the Rhine River, the prayer is a plea for God to “exact retribution for the shed blood of His servants.” (I’m using the translation in Jonathan Sacks’ Koren Siddur.) It asks God to “execute judgment among the nations, filled with the dead, crushing rulers far and wide.” Martin Luther King said, “Hate cannot drive out hate; only love can do that.” The authors of Av HaRachimim apparently disagreed.

Scholars can debate whether the medieval Jews of the Rhineland asked God to take revenge because they recognized the danger of human vengeance or because they lacked the power to take matters into their own hands. But either way, Av HaRachimim is a hateful text.

Still, there’s a crucial difference between the hate it expresses and the hate that led Crusaders to kill Jews. And in the United States today, there is no moral equivalence between people who express rage because they view others as subhuman and people who express rage because they’ve been treated as subhuman. Contrary to Dershowitz’s tweet, the “both sides” argument is not “always proper.”

Donald Trump specializes in dehumanization. He calls Central American immigrants “animals” and women “dogs” and “pigs.” He says African Americans hail from “shithole countries.”

And because Trump wields enormous power, he can translate those sentiments into policies that devastate people’s lives. Those “animals” have their children taken away.

On the other side are people who suffer from the injustices Trump wishes to reinforce. There are the rape victims who yelled at senators planning to vote for Brett Kavanaugh. There’s Maxine Waters, one of thirteen children born to a single mother, who worked in a clothing factory before becoming the congresswoman of a majority Latino and African American district composed of the kinds of people Donald Trump allegedly called “too stupid to vote for me.”

Waters is angry. After telling people to “push back on” Trump cabinet members in restaurants and department stores, she became the villain of a thousand Republican campaign ads.

But Waters has reason to be angry. African Americans, who represent just 13% of America’s population, comprise 31% of the people killed by police—yet when African American football players silently protested this fact, Trump pressured NFL owners to fire them. She has the right to be angry.

Of course, not everything that the oppressed say and do is decent, productive or true. King was right: Love is morally superior—and more politically effective—than hate.

But people don’t have to be angels to demand justice. And you can’t judge someone’s incivility and anger without understanding the history—and the power dynamics—that underlie it. It’s that history, and those hierarchies of power, that the “both sides-ism” so popular in today’s media ignores. And by ignoring that history, the media makes it easier for Trump voters to tell pollsters—with a straight face—that white people in America face more racism than do black people.

The relationship between white, black and brown Americans, and between men and women, is not a tale of Hatfields and McCoys. These aren’t ancient feuds between roughly equivalent forces whose causes have been lot in the mists of time.

White Americans committed genocide against Native Americans, enslaved black Africans, conquered and stole parts of Mexico and repeatedly invaded Central America. American women got the vote less than a century ago and marital rape only became a crime in all fifty states in 1993.

Opinion | Blaming ‘Both Sides’ For Political Rage Is Ignorant - And Immoral

Condemning the anger of Maxine Waters, or of the women protesting Brett Kavanaugh, without acknowledging this history is like condemning Jews for saying Av HaRachimim without acknowledging medieval anti-Semitism. It’s dishonest. History doesn’t stop mattering when we ignore it. It’s when we ignore it that it returns in the most dangerous ways.

Peter Beinart is a Senior Columnist at The Forward and Associate Professor of Journalism and Political Science at the City University of New York.