It is possible that, in the history of America’s radicalization spiral, the horrifying, cold-blooded assassination of the right-wing activist Charlie Kirk will be recorded as only the second-most-dangerous event of September 10, 2025. If so, the more significant development will instead have been the speech that evening by President Donald Trump.If you did not listen to Trump’s remarks, which have received only light attention from the media, you might have missed the chilling message they contained. Trump may have sounded like he was deploring violence and calling for unity. In reality, he did the opposite.The speech began and ended with encomiums to Kirk’s character and family, which is wholly appropriate. The important and dangerous passage came in a sequence of four sentences in the middle:For years, those on the radical left have compared wonderful Americans like Charlie to Nazis and the world’s worst mass murderers and criminals. This kind of rhetoric is directly responsible for the terrorism that we’re seeing in our country today, and it must stop right now.My administration will find each and every one of those who contributed to this atrocity and to other political violence, including the organizations that fund it and support it, as well as those who go after our judges, law-enforcement officials, and everyone else who brings order to our country. From the attack on my life in Butler, Pennsylvania, last year, which killed a husband and father, to the attacks on ICE agents, to the vicious murder of a health-care executive in the streets of New York, to the shooting of House Majority Leader Steve Scalise and three others, radical-left political violence has hurt too many innocent people and taken too many lives.Trump was reading from a script, so unlike many of his more clumsy statements, this bears the mark of deliberate thought.Trump’s rhetoric assumes that a left-wing activist murdered Kirk. That may well be borne out. This morning, investigators found bullets “engraved with expressions of transgender and antifascist ideology” inside the suspected murder weapon, according to The Wall Street Journal. But when the president made this claim, there was literally no evidence of this at all—not even a suspect identified by law enforcement, let alone proof of motive.[George Packer: The tragedy of Charlie Kirk’s killing]The most important move Trump made in his remarks was to define political violence as an exclusively left-wing tactic. He listed a series of events carefully selected to implicate his enemies and exonerate his allies. Trump’s list goes back to the 2017 shooting of Steve Scalise, but omits the shootings of two Democratic legislators at their homes earlier this summer. It does not mention the 2020 attempted kidnapping of Michigan Governor Gretchen Whitmer, or the brutal attack on former House Speaker Nancy Pelosi’s husband in 2022 (which Trump has used as a punch line to mock the victim).Notably, Trump’s list ignores the shooting just one month ago at CDC headquarters, in which a man protesting COVID-19 vaccines fired more than 180 shots at the building and killed a police officer, but includes “attacks on ICE agents,” which have not involved gunfire. Trump of course handed out pardons to supporters who brutalized police officers on January 6, 2021. This week, his allies in the Senate defended his bestowal of military honors upon Ashli Babbitt, who was shot trying to smash her way through the Capitol in the insurrection attempt.Every political movement in history, including the most bloodthirsty, has condemned political violence by its opponents. The only real test is whether you also oppose political violence by your allies. This is a test Trump has repeatedly failed.Because condemning political violence is a matter of principle, it remains necessary no matter which side has committed more violence. However, to the extent that Trump is implying the left bears exclusive or even disproportionate responsibility for violence, he is wrong. A 2022 study by the Anti-Defamation League (which is not a left-wing group) found that, over the previous decade, more than three-quarters of political murders in the United States resulted from right-wing motives.Having implicitly redefined political violence to exclude the political right, Trump proceeded to expand its definition far beyond violence or even incitement. He blamed Kirk’s murder on those who “compared wonderful Americans like Charlie to Nazis and the world’s worst mass murderers and criminals.”Here Trump reiterated a charge that he and his supporters made after the Butler shooting. The argument is that to compare an American political figure to a totalitarian is to justify acts of violence against them—that if you say somebody is a member of an authoritarian political movement, you must also be saying that any methods may be used to stop them.It would be perverse to create a rule that prevents Americans from frankly calling out authoritarian politicians and movements for fear that such a complaint would justify violence. Anti-authoritarian movements generally grasp that only peaceful action can preserve democratic norms and institutions, and that violence merely feeds into the cycle of escalation that erodes them.Even if one did subscribe to this strange prohibition on describing political opponents as authoritarian, however, Trump himself violates it routinely and flagrantly, likening his opponents to Communists and Nazis as a matter of course. Last year, to pick one example out of hundreds, he accused Biden of running a “Gestapo administration.” So Trump is not offering a neutral guideline for making American political debate more civil. He is proposing a rule that binds his opponents but does not protect them, and protects him and his allies but does not bind them.The breadth of Trump’s targets was notable. He called “the radical left”—a term he routinely uses to describe the entire Democratic Party—“directly responsible” for the murder, and promised that his administration would go after it, including its funding sources.Both Trump’s intentions and his capacity to follow through on his threats are unclear. Yet here is the straightforward reading of his rhetoric: The president of the United States is treating the political opposition as accessories to murder and threatening to use the full power of the government to attack it.