I can say with great confidence that Trump’s final sentence is untrue. I can do so because the September issue of The Atlantic contains an essay of mine entitled “The Rise of the Violent Left,” which discusses the very phenomenon that Trump claims “nobody wants” to discuss. Trump is right that, in Charlottesville and beyond, the violence of some leftist activists constitutes a real problem. Where he’s wrong is in suggesting that it’s a problem in any way comparable to white supremacism.

What Trump calls “the alt left” (I’ll explain why that’s a bad term later) is actually antifa, which is short for anti-fascist. The movement traces its roots to the militant leftists who in the 1920s and 1930s brawled with fascists on the streets of Germany, Italy, and Spain. It revived in the 1970s, 1980s, and 1990s, when anti-racist punks in Britain and Germany mobilized to defeat Neo-Nazi skinheads who were infiltrating the music scene. Via punk, groups calling themselves anti-racist action—and later, anti-fascist action or antifa—sprung up in the United States. They have seen explosive growth in the Trump era for an obvious reason: There’s more open white supremacism to mobilize against.

As members of a largely anarchist movement, antifa activists generally combat white supremacism not by trying to change government policy but through direct action. They try to publicly identify white supremacists and get them fired from their jobs and evicted from their apartments. And they disrupt white-supremacist rallies, including by force.

As I argued in my essay, some of their tactics are genuinely troubling. They’re troubling tactically because conservatives use antifa’s violence to justify—or at least distract from—the violence of white supremacists, as Trump did in his press conference. They’re troubling strategically because they allow white supremacists to depict themselves as victims being denied the right to freely assemble. And they’re troubling morally because antifa activists really do infringe upon that right. By using violence, they reject the moral legacy of the civil-rights movement’s fight against white supremacy. And by seeking to deny racists the ability to assemble, they reject the moral legacy of the ACLU, which in 1977 went to the Supreme Court to defend the right of neo-Nazis to march through Skokie, Illinois.

Antifa activists are sincere. They genuinely believe that their actions protect vulnerable people from harm. Cornel West claims they did so in Charlottesville. But for all of antifa’s supposed anti-authoritarianism, there’s something fundamentally authoritarian about its claim that its activists—who no one elected—can decide whose views are too odious to be publicly expressed. That kind of undemocratic, illegitimate power corrupts. It leads to what happened this April in Portland, Oregon, where antifa activists threatened to disrupt the city’s Rose Festival parade if people wearing “red maga hats” marched alongside the local Republican Party. Because of antifa, Republican officials in Portland claim they can’t even conduct voter registration in the city without being physically threatened or harassed.

So, yes, antifa is not a figment of the conservative imagination. It’s a moral problem that liberals need to confront.

But saying it’s a problem is vastly different than implying, as Trump did, that it’s a problem equal to white supremacism. Using the phrase “alt-left” suggests a moral equivalence that simply doesn’t exist.

For starters, while antifa perpetrates violence, it doesn’t perpetrate it on anything like the scale that white nationalists do. It’s no coincidence that it was a Nazi sympathizer—and not an antifa activist—who committed murder in Charlottesville. According to the Anti-Defamation League, right-wing extremists committed 74 percent of the 372 politically motivated murders recorded in the United States between 2007 and 2016. Left-wing extremists committed less than 2 percent.

Second, antifa activists don’t wield anything like the alt-right’s power. White, Christian supremacy has been government policy in the United States for much of American history. Anarchism has not. That’s why there are no statues of Mikhail Bakunin in America’s parks and government buildings. Antifa boasts no equivalent to Steve Bannon, who called his old publication, Breitbart, “the platform for the alt-right,” and now works in the White House. It boasts no equivalent to Attorney General Jefferson Beauregard Sessions III, who bears the middle name of a Confederate general and the first name of the Confederacy’s president, and who allegedly called the NAACP “un-American.” It boasts no equivalent to Alex Jones, who Donald Trump praised as “amazing.” Even if antifa’s vision of society were as noxious as the “alt-right’s,” it has vastly less power to make that vision a reality.

And antifa’s vision is not as noxious. Antifa activists do not celebrate regimes that committed genocide and enforced slavery. They’re mostly anarchists. Anarchism may not be a particularly practical ideology. But it’s not an ideology that depicts the members of a particular race or religion as subhuman.

If Donald Trump really wants to undermine antifa, he should do his best to stamp out the bigotry that antifa—counterproductively—mobilizes against. Taking down Confederate statues in places like Charlottesville would be a good start.