According to the FBI, there are now about 2,700 open domestic terrorism investigations — a number that has doubled since spring 2020 — and that doesn’t include smaller but still serious incidents that don’t rise to the level of a federal investigation. Last year, threats against members of Congress reached a record 9,600, according to data provided by Capitol Police. But it’s extremely rare for most adults to intentionally harm other people, especially for political reasons, said Rachel Kleinfeld, a senior fellow in the democracy, conflict, and governance program at the Carnegie Endowment for International Peace. Still, Ms. Kleinfeld said, there are ways to lower the average person’s tolerance for violence. If political aggression is placed in the context of war, he suggested, ordinary people with no previous history of violence are more likely to accept it. Political violence can also be made more palatable by turning it into a defensive action against a belligerent enemy. This is especially true if an opponent is persistently described as irredeemably evil or less than human. “The right one, at this point, does all three of those things at once,” Ms. Kleinfeld said. There is little evidence that Republicans and right-wing media figures have moderated their rhetoric, even as Congress and the Justice Department investigate the Jan. 6 attack. Several defendants charged in the riots said they were moved to act by Mr. Trump’s words. However, many Republicans tried to minimize his role.
