Left-Wing Violence in the U.S.: Attacks, Drivers, and Federal Response

Left-wing violence in the US in 2025 reached its highest level in more than three decades and, by one widely cited count, outnumbered right-wing attacks for the first time since the early 1990s. That count rests on five incidents logged through early July by the Center for Strategic and International Studies, including the fatal shooting of conservative activist Charlie Kirk, an armed assault on an ICE detention facility in Texas, an arson at a Republican Party headquarters, and an arrest outside the US Capitol of a man carrying incendiaries who told police he planned to kill three members of the Trump cabinet. The numbers are real, but they sit inside a longer record in which left-wing attacks have remained far less lethal than violence from the right or from jihadist actors, and the methodology behind the headline finding has been sharply contested.

The Attacks That Defined the Year

Four incidents account for most of the 2025 picture.

On January 27, Ryan Michael English, 24, of Massachusetts, was arrested near the US Capitol carrying vodka-bottle incendiary devices, knives, and a lighter. Prosecutors said he told Capitol Police he intended to kill Defense Secretary Pete Hegseth, House Speaker Mike Johnson, and Treasury Secretary Scott Bessent. A federal grand jury indicted him on charges including attempted assassination of a cabinet member nominee.¹

On March 30, an assailant set fire to the Republican Party headquarters in Albuquerque, New Mexico, and spray-painted “ICE = KKK” on the building.²

On July 4, roughly a dozen people in black-bloc tactical gear attacked the Prairieland ICE Detention Facility in Alvarado, Texas. They detonated fireworks and explosives, spray-painted vehicles, and fired live rounds at correctional officers. An Alvarado police officer was shot in the neck. Fourteen suspects were apprehended.²³⁴

On September 10, Charlie Kirk was fatally shot while speaking at Utah Valley University in Orem, Utah. Tyler James Robinson, 22, was arrested the following night after his father recognized him in surveillance images and helped arrange his surrender. Investigators recovered a Mauser bolt-action rifle near the campus, and bullet casings bore inscriptions including “Hey fascist! Catch!” Robinson was charged with aggravated murder.⁵⁶

The CSIS dataset also classified the December 2024 killing of UnitedHealthcare CEO Brian Thompson by Luigi Mangione as left-wing violence, though that label is contested. A New York judge dismissed state terrorism charges against Mangione in September 2025, ruling that his stated grievances with the healthcare industry did not amount to an intent to “intimidate or coerce a civilian population” under the state’s terrorism statute. Federal prosecutors did not charge terrorism either, though they are seeking the death penalty on murder and firearms counts.⁷

How It Compares to Right-Wing and Other Violence

Even with the 2025 spike, left-wing attacks remain far less lethal than violence from other sources. Over the past decade, left-wing attacks in the CSIS dataset killed 13 people, compared with 112 for right-wing attacks and 82 for jihadist attacks.² A University of Maryland study using the PIRUS dataset found that left-wing radicals had 68 percent lower odds of engaging in violent behavior than right-wing individuals, and globally, left-wing attacks were 45 percent less likely to result in fatalities.⁸

Tactics differ too. Twenty of the 35 left-wing attacks CSIS recorded over the past decade involved arson or incendiaries as the primary weapon, often directed at unoccupied facilities. Perpetrators frequently lack formal coordination, weapons training, and strategic planning, and they tend to select hardened government targets like ICE and law enforcement buildings that limit the potential for mass casualties.

Context on the right side of the ledger matters as well. Right-wing terrorism dropped sharply in the first half of 2025, with only one incident recorded: the June 14 assassination of former Minnesota House Speaker Melissa Hortman and her husband, Mark, by Vance Boelter, who impersonated a police officer to gain entry to their home. Boelter also shot state Senator John Hoffman and his wife, who survived. Investigators found a list of roughly 70 names in his vehicle, including lawmakers, abortion providers, and advocates. Boelter pleaded guilty to federal murder charges in June 2026 and agreed to two consecutive life terms plus 40 years.⁹ A modest increase in left-wing incidents was enough to flip the ratio because the right-wing count collapsed, a point the CSIS authors themselves acknowledged.¹⁰

Zoomed out further, broader analyses consistently attribute roughly 75 to 80 percent of domestic terrorism deaths since 2001 to right-wing extremism, with left-wing violence responsible for less than 5 percent of fatalities.¹¹

What Is Driving the Shift

CSIS analysts Daniel Byman and Riley McCabe attributed the rise in left-wing violence primarily to two forces. The first is partisan extremism, meaning attacks on elected officials and political candidates in a climate of mutual dehumanization. The second is anti-government extremism, particularly resistance to the Trump administration’s immigration enforcement and expansion of military and law enforcement authority. Of 41 left-wing incidents recorded since 2016, 17 were motivated by anti-government extremism and 11 by partisan extremism.²

Byman offered a speculative explanation for the drop on the right: many traditional right-wing grievances about immigration, abortion, and federal agencies are now embraced by the Trump administration, potentially reducing the perceived need for independent violent action. Aggressive law enforcement after the January 6, 2021, Capitol breach also caused significant disarray within groups like the Oath Keepers and Proud Boys. Byman assessed the right-wing decline as “likely temporary.”¹⁰

Underneath the incident counts, survey data suggests a troubling baseline. Research by Nathan Kalmoe and Lilliana Mason found Democrats and Republicans express similarly high levels of dehumanizing rhetoric toward the other side and comparable theoretical support for violence. Americans also dramatically overestimate the other side’s willingness to act: Democrats believe 45.5 percent of Republicans support partisan murder, and Republicans believe 42 percent of Democrats do.

Why the Headline Finding Is Contested

The CSIS claim that left-wing attacks outnumbered right-wing ones in 2025 drew a sharp methodological rebuttal. In an October 2025 article for Just Security, researchers Michael Jensen and Amy Cooter, drawing on the Terrorism and Targeted Violence (T2V) dataset, called the CSIS analysis “analytically flawed.” They argued that drawing sweeping conclusions from five left-wing incidents over seven months was statistically unreliable and that CSIS applied its inclusion and exclusion criteria inconsistently. Comparable right-wing incidents were omitted from the CSIS count, they said, including a March 2025 plot by a 17-year-old targeting President Trump and multiple school-based threats with neo-Nazi links.¹²

The T2V dataset painted a broader picture. For the first six months of 2025 it identified 154 terrorist plots and attacks, an 85 percent increase over the same period in 2024, with a 343 percent increase in deaths and a 789 percent increase in injuries. Motivations were diverse: 20 plots targeted immigration enforcement, 13 involved premeditated violence against peaceful demonstrators, and more than 30 were antisemitic in nature.

Several categories of 2025 violence sat outside the CSIS count by design. More than 20 attacks on Tesla vehicles and facilities, linked to opposition to Elon Musk’s political role, were classified as “economic vandalism” rather than terrorism. Three high-profile attacks related to the Israel-Palestine conflict were coded as “ethnonationalist.” Violent clashes between law enforcement and immigration protesters were excluded for not meeting the threshold of intending “broad psychological impact.” Jensen and Cooter noted that the CSIS findings were “quickly weaponized” by political actors, including a tweet from the White House Deputy Press Secretary labeling the American left a “clear and present danger.”

William Braniff, director of American University’s Polarization and Extremism Research and Innovation Lab, pushed the critique further at an October 28, 2025 Senate Judiciary subcommittee hearing. Citing data showing terrorism and targeted violence events averaged 2.6 per day between January 2023 and August 2025, Braniff argued the violence “does not fit neatly into any one ideological category.” Only 30 percent of cases in a Department of Homeland Security prevention database were classified by ideology at all, while 57 percent involved non-ideological personal grievances. He also disclosed that the administration had canceled funding for the T2V dataset in March 2025.¹³

The Federal Response

After the Kirk assassination, the political response escalated quickly. On September 22, 2025, President Trump signed an executive order formally designating “Antifa” as a domestic terrorist organization, describing it as a “militarist, anarchist enterprise” aiming to overthrow the US government. The order instructed executive agencies to “utilize all applicable authorities to investigate, disrupt, and dismantle” Antifa’s operations and prosecute those who fund them.¹⁴

Three days later, the administration issued National Security Presidential Memorandum 7 (NSPM-7), directing Joint Terrorism Task Forces to prioritize investigations into networks engaged in “organized political violence.” The memorandum defined the ideological threads animating targeted violence broadly, including “anti-Americanism, anti-capitalism, and anti-Christianity,” as well as “extremism on migration, race, and gender” and “hostility towards those who hold traditional American views.”¹⁵ On September 29, the Attorney General established an ICE Protection Task Force, instructed US Attorney’s Offices in Oregon and northern Illinois to charge suspects with the “highest provable offense,” and tasked the Treasury Department and IRS with tracing funding networks and scrutinizing tax-exempt organizations.¹⁶

The legal foundation for the Antifa designation is contested. No federal statute creates a domestic terrorist organization designation regime; the concept exists in federal law only for foreign organizations. The Brennan Center for Justice called the designation legally void, noting the administration “failed to cite any statute or constitutional provision” to support it and predicting that “court challenges to actions taken pursuant to these orders will likely meet with success.”¹⁷ The ACLU warned that NSPM-7’s language conflates First Amendment-protected protest and association with “criminal and terroristic conspiracies,” drawing comparisons to the FBI’s COINTELPRO program that targeted civil rights and antiwar groups in the 1960s and 1970s.¹⁸

The Legal Framework Underneath

The United States has no standalone federal criminal statute for domestic terrorism. The USA PATRIOT Act defines the term as the “deliberate use or threat of premeditated violence by nonstate actors with the intent to achieve political goals,” but attaches no criminal sanctions to that definition. Prosecutors rely instead on a patchwork of existing statutes covering conspiracy, weapons offenses, arson, RICO provisions, and assaulting federal officers. Federal law does not distinguish between left-wing and right-wing terrorism as separate legal categories, though enforcement priorities and framing shift with administrations.¹⁹

The underlying investigative load has grown regardless of label. FBI domestic terrorism investigations more than doubled between 2020 and 2023, and open cases grew by 357 percent between fiscal years 2013 and 2021.²⁰ Byman cautioned that the current dip in right-wing violence is almost certainly temporary, and that crackdowns on peaceful organizations may “strengthen extremist narratives that peaceful politics will inevitably fail.”

1
U.S. Department of Justice. Bay State Resident Charged in Alleged Attempt to Assassinate Cabinet Member Nominee
2
CSIS. Left-Wing Terrorism and Political Violence in the United States
3
U.S. Department of Justice. Antifa Cell Members Convicted in Prairieland ICE Detention Center Shooting
4
BBC News. Prairieland ICE Detention Center Attack Sentencing
5
PBS NewsHour. Suspect in Custody for Charlie Kirk Shooting
6
NPR. Charlie Kirk Shooting Manhunt Suspect Custody Timeline
7
New York State Courts. People v. Luigi Mangione, Omnibus Decision
8
PNAS. Ideological Violence Across Extremist Groups
9
PBS NewsHour. Man Pleads Guilty to Killing a Minnesota Lawmaker and Her Husband
10
CSIS. Ideological Trends in U.S. Terrorism
11
PBS NewsHour. Right-Wing Extremist Violence Is More Frequent and Deadly Than Left-Wing Violence, Data Shows
12
Just Security. Correctly Assessing Left-Wing Terrorism and Political Violence in the United States
13
U.S. Senate Committee on the Judiciary. Testimony of William Braniff
14
The White House. Designating Antifa as a Domestic Terrorist Organization
15
The White House. Countering Domestic Terrorism and Organized Political Violence
16
U.S. Department of Justice. AG Memorandum: Ending Political Violence Against ICE
17
Brennan Center for Justice. Trump’s Orders Targeting Antifascism Aim to Criminalize Opposition
18
ACLU. How NSPM-7 Seeks to Use Domestic Terrorism to Target Nonprofits and Activists
19
Harvard Law Review. Responding to Domestic Terrorism: A Crisis of Legitimacy
20
U.S. Government Accountability Office. Countering Domestic Terrorism