Last year, 39 of the 50 killings committed by political extremists, according to the Anti-Defamation League , were carried out by white supremacists. Another eight were committed by killers with anti-government views. Over the past 10 years, right-wing extremists were responsible for more than 70 percent of extremist-related killings. “Right-wing extremist violence is our biggest threat,” Jonathan Greenblatt, the head of the A.D.L., has written. “The numbers don’t lie.”

The latest example came on Saturday in El Paso when a 21-year-old white man apparently killed 20 people, after having first announced in a manifesto that his attack was a response to “the Hispanic invasion of Texas.” His language mimicked the language that Trump has used.

Yes, I understand that there are important caveats to add. Conservative America is mostly filled with honorable people who deplore violence and bear no responsibility for right-wing hate killings. Some mass shootings have no evident political motive, like the one in Dayton, Ohio, on Sunday. And liberal America also has violent and deranged people, like the man who shot at Republican members of Congress playing softball in 2017. Some Democratic politicians have also occasionally lapsed into ugly, violent rhetoric and suggested they want to punch their political opponents.

But it’s folly to pretend that the problem is symmetrical. Mainstream conservative politicians use the rhetoric of physical violence much more often, starting with the current president of the United States. And right-wing extremists have a culture of violence unlike anything on the left. Its consequences are fatal, again and again.

Over the years, Republicans have sometimes called on Muslim leaders to ask themselves why their religion has produced a disproportionate share of the world’s terrorist attacks — and to do something about the situation. I’d urge those Republicans to take their own advice. Right-wing terrorism is killing far more Americans these days than Islamist terrorism.