Political speech inspires belief, and action.

This shouldn’t be controversial, but it is. Assassination attempts against public figures who have been singled out for abuse by President Trump, and the massacre at a Pittsburgh synagogue, have refocused attention on Trump’s incendiary rhetoric. He dismissed the idea that he might have any reason to “tone down” his language amidst the violence, suggesting that he might “tone it up” instead. And he has continued to attack some of those targeted by the mail bombs, including CNN, George Soros, and Tom Steyer. The president’s apologists have duly returned to their mantra that the president’s rhetoric is just a sideshow. Extremist political violence is written off as either radical evil or sociopathy, having no causes, and the president’s language is minimized as having no effects. He can’t possibly have made people so much worse.

But he can have set out a horrifyingly false vision of calling them to be better.

Political speech is aspirational; it moves listeners to believe and act differently. It offers an idea of a shared good and calls on the audience to live up to it. From Pericles’ funeral oration to Lincoln’s Gettysburg Address, the solemn commemoration of the wartime dead has been an occasion to define a moral vision of the war’s stakes and to call on the audience to recommit to achieving it. Churchill’s St. Crispin’s Day-like “we will fight them on the beaches” similarly sought to instill determination. But it applies in peacetime as well. Reagan’s “city on a hill,” Kennedy’s “ask what you can do for your country,” and Roosevelt’s “the only thing we have to fear is fear itself” all aimed to move and motivate their audiences. They offered visions of what political goods were worth fighting for, and tried to inspire the necessary shared work.

No one should treat politicians’ words as the primary source of their moral motivation or direction. But politics is about persuasion as well as coercion, and politicians are skilled at persuading large audiences. Words can fan the spark of a listener’s desire to do the right thing, and channel that desire toward a particular cause. The speaker can’t know all the actions their words will inspire. But that doesn’t lead us to doubt the words’ power.

President Trump certainly doesn’t act like someone who thinks his own words are inconsequential. Between his Twitter account and his campaign rallies, he may spend more time directly addressing the public than any previous president. He’s well aware of the way that a scornful nickname can wound an opponent’s public standing. He shows a clear conviction that he can speak to his supporters in a way that can move and motivate them; his speech is aspirational. The question is what he calls them to aspire to.

Trump tells Americans, day after day, that their country is under threat, that it is being invaded by an “infestation” of people he dehumanizes as really being “animals,” that the nefarious “globalist” Jewish philanthropist Soros is subsidizing the invasion. He praises a Republican Congressman who assaulted a reporter, encourages his listeners to “kick the crap out of” protestors, demonizes the press as the “enemies of the people.” These words fan the spark of listeners’ desire to defend their country, and directs their anger against reporters, immigrants, Hispanics, African-Americans, “globalist” Jews, women, Democrats. Less frequently but sometimes he spreads the white nationalist story of a white race under threat around the world, from the frontiers of Europe to the streets of Sweden. His false image of immigration-driven catastrophe in Europe is particularly evocative, since he pairs it with a warning that the US could go down the same path if the invaders aren’t fought off.

Trump of course can’t predict all the actions his listeners will take. What he primarily cares about is motivating them to vote Republican. But he sets a moral mood. The question is not whether he sincerely wants violence in his heart. The words themselves are the relevant fact, in a shared political life shaped by speech.

Analysts have used the concept of “norm erosion” to describe Trump’s effects on the conventions of public life: truth-telling, financial disclosure, avoiding conflicts of interest, respect for the independence of criminal investigations. Norm erosion encourages cynicism, indifference: nothing matters. Trump’s scorn for ceremonial speech he dismisses as boringly “presidential” is a kind of norm erosion. Arguably his smirking approval of violence is, too.

But his steady stream of fury and abuse is something else; it’s norm inversion. The threats to America matter very much. In his way, he defines a cause for his audience to fight for and calls on them to do so. When he praised the “very fine people” among the far-right protestors in Charlottesville last year, he wasn’t complimenting their private lives. He was admiring them for turning out to stand up for a Robert E. Lee statue and the symbols of the Confederacy. This sends a message to other listeners about what’s admirable.

Some of those who listen are, as we say in other contexts, “radicalized.” This isn’t a matter of following the speaker’s orders. Indeed, they may come to view the speaker as insufficiently radical, not really devoted to the cause, as the Pittsburgh killer seems to view Trump. That doesn’t mean that the radicalizing speech had no effect. Like other aspirational political speech, it can shaper the listener’s view of the moral world, of what is worth fighting for against whom.

Pre-Trump conservatives prided themselves on being heirs to the long tradition of critiques of democracy as vulnerable to demagogues, a critique that depends on the thought that the demagogue’s speech actually persuades large numbers of people. Donald Trump didn’t tell anyone to put bombs into the mail or to open fire at a synagogue. The men who did those things are responsible for their own actions. But Trump, along with his allied media outlets, stoked the requisite anger and belief in enemies—not just opponents, but enemies— who have to be fought. “Ideas have consequences” was a favorite saying of pre-Trump conservatives. So do the words that carry them.