A think tank report on political violence published a day after Charlie Kirk’s murder found right-wing violence has killed many more Americans than left-wing attacks over the past half century. Conservatives quickly condemned the report and called for its withdrawal.
Speaking at Kirk’s memorial service, President Donald Trump reassured the crowd, “The violence comes largely from the left.”
But that’s not what two recent studies show.
The Cato Institute, a libertarian think tank co-founded by energy billionaire Charles Koch, released its report on politically motivated murder Sept. 11, the day after the conservative icon Kirk was murdered at a Utah college. The study offers two main conclusions:
- “Politically motivated murder is very uncommon in the United States.”
- Right-wing terrorists have killed six times as many Americans as left-wing terrorists in the past 50 years.
Cato blamed political violence from the right for the deaths of 391 people since 1975, or 63% of the total of 618 deaths. Liberal violence killed 65 people during the same period, or 10% of the total. (These figures omit the deaths from the 9/11 attacks on the U.S. that were motivated by foreign Islamists.)
Cato blamed political violence from the right for the deaths of 391 people since 1975, or 63% of the total of 618 deaths.
The American Enterprise Institute, a conservative think tank, responded with a critique of Cato’s report: “The Shoddy Efforts to Pin Political Violence on the Right.”
“Liberals rely on skewed studies to claim right-wing violence is more common” said the conservative news outlet the Washington Examiner.
“The ‘Study’ You’re Citing About Right-Wing Violence Is Full Of Fake Data,” crowed The Federalist.
“Conservative Leaders Urge the Cato Institute to Withdraw Its Deeply Flawed Political Violence Study,” said Richard Viguerie’s Conservative HQ.
The report “is rife with methodological errors and contributes to an empirically false claim that ‘right wing violence is on the rise’ at a time when the American right is being targeted repeatedly by left wing violence,” said Conservative HQ.
Critics said the Cato study used flawed data, and some said the study results were biased against conservatives because it only went back to 1975, omitting the 1960s and early 1970s, a period that saw many left-wing attacks inspired by opposition to the U.S. war in Vietnam.
The author of the Cato study addressed some of the complaints in a follow-up post, “Answering the Critics.”
In one section, he wrote: “The Trump administration deleted a Department of Justice research paper that supported my findings. In fact, the DOJ report found that right-wing terrorists killed 520 people and left-wing terrorists killed 78 since 1990. If the DOJ numbers are to be believed, my research undercounted left-wing politically motivated terrorist killings by 37 and right-wing killings by 168. According to them, I missed an entire additional equivalent of an Oklahoma City Bombing committed by right-wing killers.”
He concluded: “Some (criticisms of the report) have a kernel of truth that disappears after a moment of thought, and others are entirely off the mark. Why are there so many poor criticisms? Many people want to talk about how upset they are with the few killings that do occur, have another reason to complain about the other political party they dislike, or yell at the people who do not operate in a pure feelings-based political debate.”
A second think tank, the Center for Strategic and International Studies, released its study on political violence on Sept. 25: “Left-Wing Terrorism and Political Violence in the United States: What the Data Tells Us.”
CSIS’s lengthy and detailed report found left-wing violence had increased during the past decade as Trump rose in political prominence. During the same time, it said, right-wing violence “sharply declined.”
“2025 marks the first time in more than 30 years that left-wing terrorist attacks outnumber those from the violent far right.”
“So far, 2025 marks the first time in more than 30 years that left-wing terrorist attacks outnumber those from the violent far right,” said the report.
Still, left-wing violence has not caught up with right-wing attacks: “In the past decade, despite the increase in the number of left-wing incidents, left-wing attacks have killed 13 victims, compared with 112 and 82 victims for right-wing and jihadist attacks, respectively.”
“The rise in left-wing attacks merits increased attention, but the fall in right-wing attacks is probably temporary, and it too requires a government response,” said the report.
The CSIS report concluded with a section, “What Is to Be Done?” offering suggestions on responding to political violence. Here are some of the ideas:
- “First, the government should avoid overreacting with crackdowns on peaceful organizations, which will serve to strengthen extremist views. Radicals will argue that peaceful politics will inevitably fail and that only violence will make a difference.”
- “Second, it is important to resource all dimensions of the terrorism threat. Left-wing terrorism is a Trump administration priority, but jihadist terrorism also remains a concern even though it has declined. Right-wing terrorism could come roaring back, especially if in 2028 there are complaints of a ‘stolen election’ or similar incendiary claims.”
- Third, “U.S. political leaders and activists need to lead by condemning violence on their side and calling for calm when it involves violence on the other side.”
People who are loyal to an ideological tribe have a tendency to focus on the abuses of their foes while excusing the misdeeds of their friends. But CSIS says this psychology of tribal loyalty feeds into dangerous assumptions that may actually increase violence: “Although the vast majority of Americans would never commit partisan violence and oppose it, widespread polarization and misperceptions that the other side is far more violent than it actually is creates a dangerous environment where extremists can more easily rationalize using violence.”