President Donald Trump’s latest move to designate antifa as a “major terrorist organization” has sparked a new wave of debate and concern across the United States, raising questions about legality, free speech, and the future of political protest. The announcement, made during Trump’s state visit to the United Kingdom on September 17, 2025, and echoed early the following morning in a series of social media posts, marks an escalation in the administration’s rhetoric against left-wing activism and comes in the wake of the killing of conservative commentator Charlie Kirk.
Trump’s declaration was nothing if not emphatic. “I am pleased to inform our many U.S.A. Patriots that I am designating ANTIFA, A SICK, DANGEROUS, RADICAL LEFT DISASTER, AS A MAJOR TERRORIST ORGANIZATION,” he wrote on his Truth Social platform, as reported by CBS News and Al Jazeera. He added, “I will also be strongly recommending that those funding ANTIFA be thoroughly investigated in accordance with the highest legal standards and practices. Thank you for your attention to this matter!”
The president’s message was clear: he intends to pursue not only the activists involved in antifa, but also those who might be supporting them financially. This, he said, would involve “thorough investigations” and the “highest legal standards.” Yet, as The Guardian and Bloomberg both noted, there was a conspicuous lack of detail from the White House about how such a designation would be carried out—or even if it’s legally possible.
Antifa, short for “anti-fascists,” is not a single organization but rather an umbrella term for a loosely affiliated network of far-left militant groups. These groups are known for their opposition to fascists, neo-Nazis, and white supremacists, particularly at demonstrations. The movement has no formal leadership, membership lists, or clear organizational hierarchy, making it a tricky target for any government attempting to apply a label typically reserved for structured, foreign terrorist organizations.
Legal scholars have been quick to point out the unprecedented nature of Trump’s plan. According to Al Jazeera, Mary McCord, a former senior Department of Justice official, stated that “there is no mechanism for ‘designating domestic organizations as terrorist organizations,’” adding that such a move would “raise significant First Amendment concerns.” The State Department’s list of terrorist organizations, which enables the prosecution of those who provide material support to listed groups, is exclusively for foreign entities. No such legal infrastructure exists for domestic groups, in part because of the broad protections the First Amendment affords to Americans’ rights of speech and assembly.
The difficulty of designating antifa as a terrorist organization is not a new issue for Trump. He threatened a similar designation during his first term in 2020, in response to widespread protests following the killing of George Floyd. At that time, as BBC and CBS News reported, the administration never followed through, likely due to the same legal obstacles and the amorphous nature of antifa itself. Former FBI Director Christopher Wray testified before Congress that year, unequivocally stating, “Antifa is a movement or an ideology, not an organization.” Without a hierarchical structure, Wray explained, it lacks the qualities that would typically allow for such a designation by the federal government.
The timing of Trump’s latest announcement is no accident. It follows the September 10, 2025, assassination of Charlie Kirk, a prominent conservative activist and founder of Turning Point USA, during a campus event in Utah. Authorities have charged 22-year-old Tyler Robinson with murder, but have not disclosed a motive. Nevertheless, Trump and his allies have been quick to blame “radical left political violence,” with the president vowing to “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 reported by CBS News.
White House officials have signaled that the administration intends to “dismantle a vast domestic terror movement” they claim is linked to left-wing activists and, by their account, to Kirk’s killing. Stephen Miller, the White House deputy chief of staff, told Al Jazeera, “We’re going to channel all of the anger that we have over the organised campaign that led to this assassination, to uproot and dismantle these terrorist networks.”
Not everyone is convinced by the administration’s narrative. Critics argue that the White House is using the tragedy as a pretext to target political opponents. As legal experts have pointed out, the lack of evidence tying antifa or its supporters directly to Kirk’s murder, and the absence of a clear organizational structure, make the president’s plan both controversial and potentially unenforceable.
Still, the move has found support among some Republican lawmakers. Senator Bill Cassidy of Louisiana praised the announcement, stating, “Antifa seized upon a movement of legitimate grievances to promote violence and anarchy, working against justice for all. The President is right to recognize the destructive role of antifa by designating them domestic terrorists.” Cassidy and Senator Ted Cruz of Texas had previously introduced a resolution in 2019 to condemn antifa’s violent acts and to designate the group a domestic terror organization, though that effort stalled in Congress.
The fallout from Kirk’s murder has extended beyond the White House and Congress. Other administration officials have taken steps to curb negative commentary about Kirk in the wake of his death. Vice President JD Vance encouraged Americans to call the employers of people criticizing Kirk, according to Politico, while Attorney General Pam Bondi briefly suggested prosecuting hateful speech before walking back her comments. Defense Secretary Pete Hegseth has reportedly initiated suspension processes for service members who made negative comments about Kirk.
The controversy has even spilled into the media world. On the night of Trump’s announcement, ABC indefinitely suspended Jimmy Kimmel’s late-night show following complaints about his comments regarding Kirk’s killing. Trump celebrated the decision, calling it “Great News for America: The ratings challenged Jimmy Kimmel Show is CANCELLED,” though the network has not made a final decision on the show’s future.
For many observers, the debate over designating antifa as a terrorist organization is about more than legal technicalities. It’s a flashpoint in the ongoing struggle over the boundaries of protest, free speech, and the government’s power to define and combat “domestic terrorism.” With the president’s announcement, those boundaries are being tested yet again, and the nation—already deeply polarized—will be watching closely to see what comes next.
