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10/21/2024 | Press release | Distributed by Public on 10/21/2024 14:21
The Rising Threat of Anti-Government Domestic Terrorism: What the Data Tells Us
The Rising Threat of Anti-Government Domestic Terrorism: What the Data Tells Us
Photo: Chip Somodevilla/Getty Images
Published October 21, 2024
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The Issue
The number of domestic terrorist attacks and plots against government targets motivated by partisan political beliefs in the past five years is nearly triple the number of such incidents in the previous 25 years combined, according to new CSIS analysis of 30 years of domestic terrorism data in the United States. This includes attacks and plots against elected officials, political candidates, political party officials, and political workers from terrorists with opposing political views. This rising threat warrants continued efforts to increase protective security measures of government targets, strengthen response plans in the event of a successful attack, and counter the spread of disinformation, conspiracy theories, and violent rhetoric that have motivated many attackers.
Introduction
In late 2022, Solomon Peña, a former candidate for the New Mexico House of Representatives, found himself at the center of a violent political vendetta. After losing the election in a landslide to his Democratic opponent, Peña refused to accept the legitimacy of the results and embarked on a campaign of violent retribution.1 In December 2022, Peña allegedly recruited four men to carry out a series of shootings targeting the homes of Democratic officials in Albuquerque, New Mexico.2 Over the course of several weeks, from early December into January 2023, Peña orchestrated a string of attacks in which gunmen fired at the homes of multiple Democratic politicians. No one was injured in the incidents, but during one of the attacks three gunshots were fired into the bedroom where a state representative's 10-year-old daughter was sleeping.3
Peña's arrest in mid-January 2023 brought an end to the violent chapter, but it also underscored a troubling increase in recent years in the number of domestic terrorist attacks motivated by partisan political beliefs. To better understand the trends in U.S. domestic terrorism, the Center for Strategic and International Studies (CSIS) compiled a dataset of 725 terrorist attacks and plots in the United States between January 1, 1994, and April 30, 2024.4 This brief analyzes the dataset for attacks and plots against government targets, and it yields three main findings.
First, there is an increased terrorist threat against government targets today. Specifically, since 2016 there has been a dramatic rise in attacks and plots motivated by partisan political beliefs. This includes attacks and plots against elected officials, political candidates, political party officials, political staff and workers, and their offices from terrorists with opposing political views. From January 1, 2016, to April 30, 2024, there were a total of 21 such terrorist attacks and plots, compared to a total of just two such incidents in the more than two preceding decades tracked in the CSIS dataset. This elevated threat is in large part due to the increased spread of conspiracy theories that motivate extremists to take violent action.
Second, there has been a significant shift in the ideologies and organization of anti-government terrorists. From 1994 to 2004, 71 percent of attacks and plots against government targets were inspired by general opposition to federal authority, spearheaded by the broader American militia movement. Today, terrorists attacking government targets are more likely to be motivated by partisan political beliefs and rarely have material ties to any group. From 2016 to 2023, only 29 percent of attacks and plots against government targets were inspired by general opposition to federal authority, while a remarkable 49 percent were inspired by partisan political views.
Third, the lethality of attacks against government targets remains low. Since 9/11, only four victims have been killed in attacks against government targets, excluding military and law enforcement targets, which were coded separately in the CSIS data. The low fatality count is attributable to the hardened nature of government targets and the limited intent and low skill of many perpetrators, though there remains the risk that government targets may be successfully attacked in locations with fewer security measures.
The remainder of this brief is divided into five sections. The first provides an overview of terrorism and outlines the dataset used in this analysis. The second analyzes trends in terrorist incidents directed at government targets in the United States. The third examines the increased threat of attacks motivated by partisan political beliefs. The fourth assesses the lethality of terrorist attacks against government targets. The final section provides brief policy implications.
Defining Terrorism and Building the Dataset
This analysis focuses on terrorism, which is defined here as the deliberate use or threat of premeditated violence by nonstate actors with the intent to achieve political goals by creating a broad psychological impact of fear or intimidation.5 For inclusion in the dataset, events had to meet all parts of this definition.
The two assassination attempts of former president Donald Trump in the summer of 2024 lie outside of the scope of this analysis. Both events occurred after the end date of data collected for this project, and investigations are ongoing-making it more difficult to come to a definitive judgment as to perpetrator motivation. Nonetheless, the attempts to kill the former president and Republican nominee for president serve as a disturbing reminder of the threat of political violence.6
This brief does not analyze the broad topics of hate speech or hate crimes, which are nevertheless clearly concerning. There is some overlap between hate crimes and terrorism since some hate crimes include the use of violence and are intended to have a broad psychological impact. However, many hate crimes were excluded from the dataset for their lack of premeditation or their low level of violence. This brief also does not include many cases of other forms of civil disturbance or criminal activity, such as rioting, street violence, mass shootings, and economic sabotage. Even though some instances of these activities do meet the definition of terrorism and are included in the dataset, in many cases the perpetrators lacked political goals, explicitly avoided harming people, did not premeditate their attacks, or did not seek to have a broader psychological effect.
Using this definition, CSIS compiled and analyzed a dataset of 725 terrorist attacks and plots in the United States between January 1, 1994, and April 30, 2024.7 The dataset includes information such as incident date, location, target and location type, weapon used, and fatalities, as well as perpetrator age, sex, ideology, group affiliation, and current or former affiliation with the military or law enforcement. A full methodology and codebook for the dataset is linked at the end of this brief.
The Terrorist Threat Against Government Targets
Over the past four years, terrorist attacks and plots in the United States have primarily been directed at government, military, and law enforcement targets. As shown in Figure 1, from January 2020 to April 2024, 50 attacks or plots have been directed at such targets. This is followed by 38 incidents targeting private individuals, 19 targeting religious institutions, and 13 targeting demonstrators.
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Program Manager and Research Associate, Warfare, Irregular Threats, and Terrorism Program
Programs & Projects
Remote Visualization
Since 1994, the number of attacks and plots against government, military, and law enforcement targets has risen and fallen dramatically at various points. However, there is a discernable increase in the number of attacks and plots against these targets beginning in the late 2000s that remains at elevated levels today, as shown in Figure 2.
Remote Visualization
Among government, military, and law enforcement targets, government targets were subject to the highest and most consistent number of attacks and plots from 1994 to 2023. Government targets include local, state, and federal government buildings and workers, as well as elected officials, candidates, political party officials, political staff, and their offices. They also include government employees-excluding military and law enforcement personnel-in their private residences, public areas, or any other locations if they were targeted because of their work or role in the government.
It is difficult to discern significant trends in the number of attacks and plots against government targets given the relatively low number of incidents each year. However, there is an elevation in the number of attacks and plots against government targets from 2016 to 2023, as shown in Figure 3. During this period, the number of terrorist attacks and plots against government targets reached levels comparable to those in the late 1990s. Figure 4 shows attacks and plots against government targets as a percentage of overall attacks and plots, which generally mirrors these trends.
Unsurprisingly, the greatest number of terrorist attacks against government targets occurred in Washington, D.C., as shown in Figure 5. The specific types of locations where attacks occur are analyzed later in this brief.
Remote Visualization
The Growing Threat Along Party Lines
To understand the factors driving fluctuations in the number of attacks and plots against government targets, including the elevated threat since 2016, it is necessary to analyze the ideologies motivating the perpetrators. In the past 30 years, the most common motive has been general anti-government sentiment.8 In the dataset, these general anti-government beliefs have been separated from more specific ideologies that also motivate attacks and plots against government targets, such as anarchism, Salafi-jihadism, white supremacy, environmentalism, and the sovereign citizen movement. The dataset also distinguishes between attacks motivated by general anti-government sentiment and those motivated by partisan political beliefs.
Analysis of these ideologies over time reveals a concerning increase in the threat of attacks against government targets motivated by partisan political beliefs. Since 2016, there has been a significant rise in the number of attacks and plots against elected officials, candidates, political party officials, political staff and workers, and their offices. The recent increase of these attacks, which were rare in the two preceding decades, are shown in Figure 6.
Remote Visualization
This increase is probably attributable to several factors. Most significant is the spread of conspiracy theories surrounding U.S. elections. In particular, claims that the 2020 presidential election was unfairly stolen from former president Trump inspired several attacks and plots, not limited to the attack on the U.S. Capitol on January 6, 2021. Less than two weeks after the attack on the Capitol, Ian Benjamin Rogers and Jarrod Copeland devised a plan to destroy the John L. Burton Democratic Headquarters in Sacramento because they believed the 2020 presidential election was rigged. Upon their arrest, law enforcement officers seized 45 to 50 firearms, thousands of rounds of ammunition, and five pipe bombs.9 More than a year and a half later, on October 28, 2022, David DePape broke into the San Francisco home of U.S. speaker of the House Nancy Pelosi, seeking to hold her hostage, and attacked her husband. DePape was motivated by a mix of conspiracy theories, including that Nancy Pelosi and other Democrats were responsible for undermining the integrity of the 2020 presidential election.10
Beyond incidents related to the 2020 presidential election, the erosion of trust in U.S. elections has fueled additional attacks, including Solomon Peña's series of shootings at the homes of various Democratic politicians after he denied that he lost his race in the November 2022 New Mexico state elections.11
Increased levels of polarization and the mainstreaming of violent political rhetoric in general also likely contribute to the increase of terrorist attacks and plots motivated by partisan political beliefs. On September 19, 2020, Pascale Ferrier sent threatening letters containing homemade ricin to then-president Trump, which were intercepted before they reached the White House.12 In a statement she read to the court during her sentencing in 2023, Ferrier said, "The only regret I have is that it didn't work, and I couldn't stop Trump."13 Ferrier's case is one of multiple that appear motivated by political differences, reflecting what happens when the broader trend of growing dislike between political parties is taken to its most extreme.14
The rise in attacks and plots motivated by partisan political beliefs represents a significant shift in the ideologies and organization of anti-government terrorists. From 1994 to 2004, 71 percent of attacks and plots against government targets were inspired by general opposition to federal authority. This wave of attacks was spearheaded by the broader American militia movement, which emerged as a reaction to perceived government overreach, fueled by concerns about gun control, federal regulations, and a growing mistrust of the federal government.15 The movement was galvanized by the 1992 Ruby Ridge standoff in Idaho, where a confrontation between federal agents and the family of Randy Weaver resulted in three deaths, and the 1993 Waco siege in Texas, where a standoff between the Branch Davidians and federal agents ended in a deadly fire, killing over 80 people. These incidents reinforced the belief among American militia groups that the federal government was an oppressive force infringing on personal freedoms.
The Oklahoma City bombing in 1995-carried out by Timothy McVeigh, a former soldier with militia sympathies-was a major turning point, as it drew widespread attention to the movement. Though McVeigh acted largely independently, his anti-government ideology aligned with that of many militia members and also had elements of white supremacy.16 After the bombing, public and law enforcement scrutiny increased, leading to a decline in militia activity and fewer terrorist attacks and plots against government targets.17 The indiscriminate deaths of many people in the bombing, including 19 children, also caused divisions within the anti-government movement. The rise and fall of this movement can be seen in Figure 7, in which attacks motivated by general anti-government beliefs declines in the late 1990s.
Remote Visualization
Since 2016, there has been a rise in the number of attacks and plots against government targets. However, unlike the attacks of the American militia movement decades prior, this rise is largely comprised of attacks and plots motivated by partisan political beliefs, as shown in Figure 7. From 2016 to 2023, only 29 percent of attacks and plots were inspired by general opposition to government authority, and a remarkable 49 percent were inspired by such partisan views.
This ideological shift may indicate a transition in extremist culture, moving away from general opposition to the federal government and toward attacks based on a target's specific political party affiliation. However, since only a small fraction of extremists plot or carry out terrorist attacks, these acts do not necessarily reflect a broader movement's attitudes or culture.
Although American militia groups are responsible for a few recent terrorist attacks and plots, such as the Wolverine Watchmen who plotted to kidnap Michigan governor Gretchen Whitmer in 2020, the vast majority of anti-government incidents since 2016 involve radicalized individuals with no material ties to any group. This finding is consistent with recent assessments from the Federal Bureau of Investigation (FBI) and Department of Homeland Security (DHS). As the FBI's 2021 Strategic Intelligence Assessment and Data on Domestic Terrorism report stated, "The greatest terrorism threat to the Homeland we face today is posed by lone offenders, often radicalized online, who look to attack soft targets with easily accessible weapons."18
It is also the case that many extremist groups have adopted decentralized structures that encourage individuals or small groups to act on their own without direct orders from leadership so that it is more challenging for law enforcement to track and prevent violent actions. In its latest assessment of domestic violent extremism, the U.S. intelligence community found that lone-wolf actors or small cells are more likely to carry out domestic terrorist attacks than domestic organizations that advocate violent extremist ideologies.19 At the same time, because groups are typically easier for counterterrorism authorities to monitor, plots by such groups may be more frequently disrupted before they reach the necessary stage to be included in the CSIS dataset.
Low Fatalities in Anti-Government Attacks Since 9/11
Despite the many terrorist attacks and plots against government targets since 9/11, such incidents have resulted in remarkably few deaths. In the past 23 years, only four victims have been killed in attacks on government targets-again, excluding attacks on military and law enforcement targets, which were coded separately in the CSIS dataset. Fatality counts remain low despite the recent rise in the number of attacks on government targets since 2016, as shown in Figure 8.
Remote Visualization
This phenomenon is probably attributable to three key factors: hardened targets, perpetrators' intent, and the level of perpetrators' skill.
First, the low number of fatalities associated with attacks on government targets is in large part due to the hardening of government targets by a variety of security measures. In the past 30 years, nearly 75 percent of all anti-government attacks have occurred at government buildings or political offices, as shown in Figure 9. These locations are often protected by physical fortifications and security personnel, making it more difficult for perpetrators to kill targets during an attack. For example, on May 22, 2023, 19-year-old Sai Varshith Kandula drove a rented U-Haul truck into security barriers around the White House, attempting to gain access to the building to seize political power. According to his guilty plea, Kandula's intent was to take control of the U.S. government and institute a dictatorship fueled by Nazi ideology. Kandula admitted to investigators that he would have killed the president and others if necessary to achieve his objective.20 However, his efforts seem foolish considering the security measures present at the White House.
Remote Visualization
Other locations where anti-government attacks occur are also often hardened by security measures. For example, in June 2022, Nicholas Roske traveled across the country to the home of U.S. Supreme Court justice Brett Kavanaugh with plans to assassinate the justice for his leaked ruling overturning Roe v. Wade. Roske arrived at Kavanaugh's residence with a Glock 17 pistol, ammunition, zip ties, a tactical knife, pepper spray, a hammer, a screwdriver, a nail punch, a crowbar, duct tape, a pistol light, and boots padded to be stealthy.21 Ultimately, he did not go through with the attack, deterred by law enforcement stationed outside the home.
In some instances, however, lower-profile targets are not afforded the same security measures at their personal residences. On July 19, 2020, Roy Den Hollander, a self-proclaimed "men's rights lawyer," posed as a FedEx deliveryman and attacked the family of U.S. district judge Esther Salas, fatally shooting her 20-year-old son, Daniel Anderl, and critically wounding her husband, Mark Anderl, at their New Jersey home. Hollander was motivated by his escalating hatred of women and growing frustration with the legal system.22 Judge Salas had presided over one of Hollander's cases involving male-only military drafts.23
Of the four lethal attacks against government targets since 2001, two occurred at personal residences, one occurred at an airport and the other at a U.S. government building. In all four instances, the perpetrators used firearms to conduct their attack. See Figure 10 for a breakdown of the weapons used in attacks on government targets during that period.
Remote Visualization
The second reason attacks against government targets have produced very few fatalities in the past two decades is that perpetrators' intent was typically not to cause mass casualties but rather to target specific individuals or limited groups. Perpetrators who attack government targets often aim to kill or intimidate figures who represent political power or policies they oppose. These attackers often choose methods designed to strike with relative precision, such as by sending mail bombs or directing their gunfire at specific individuals. For example, on February 14, 2022, Quintez Brown entered the campaign office of Craig Greenberg, a Democratic mayoral candidate in Louisville, Kentucky. Armed with a handgun, Brown fired multiple shots at Greenberg and his staff. None of the bullets hit anyone directly, but one did graze Greenberg's sweater. Brown, a former columnist and activist known for his involvement in racial justice and anti-violence efforts, appears to have been disillusioned with the political establishment and targeted Greenberg simply because he was running for mayor.23 In many such attacks on government targets, perpetrators are motivated by specific political grievances, leading them to target only one or a small number of individuals rather than indiscriminately killing bystanders. This limited scope contributes to the overall low fatality count of attacks on government targets.
The third reason attacks against government targets have been largely unsuccessful in causing fatalities is that, in most cases, the perpetrators lack the weapons and tactical training to maximize their impact. For example, on July 13, 2019, Willem Van Spronsen carried out an attack on an Immigration and Customs Enforcement (ICE) facility in Tacoma, Washington, which he had referred to as a "concentration camp" in a manifesto he left behind.24 Spronsen was armed with a semi-automatic rifle and flares, which he attempted to use to ignite a large propane tank and threw at buildings.25 However, propane tanks are designed with safety mechanisms to prevent accidental ignition, and the buildings of the facility were concrete and therefore non-flammable.26 Spronsen failed to cause significant damage to the facility and did not harm anyone before he was shot and killed by responding police officers.
In addition to limiting the effectiveness of terrorist attacks, poor training means perpetrators may reveal plots for attacks before they can occur. Poor operational security practices-particularly the use of social media-have assisted investigators in disrupting many plots recorded in the CSIS dataset.
The hardened nature of many government targets and the limited intent and low skill of many perpetrators have all contributed to low fatality counts despite the elevated number of domestic terrorist attacks and plots on government targets in recent years.
Policy Implications
The number of domestic terrorist attacks and plots against government targets motivated by partisan political beliefs in the past five years is nearly triple the number of such incidents in the previous 25 years combined, according to new CSIS analysis of 30 years of domestic terrorism data in the United States. Considering these worrisome trends, and with a better understanding of the motivations and the level of danger posed by anti-government terrorists, this section outlines several recommendations for policymakers and law enforcement. The goal of these recommendations is to bridge ideological divides and help build more effective counterterrorism measures.
First, the rising threat of terrorism against government targets motivated by partisan political beliefs warrants continued efforts to increase protective security measures for elected officials, candidates, political party officials, and political staff and workers. In response to high-profile attacks and increasing numbers of threats against members of Congress, their staff, political candidates, and other political workers, Congress has in recent years authorized additional spending on a variety of measures, including strengthening Capitol security and improving personal security for lawmakers.27 Congress has also funded annual budget increases for investigative and security forces responsible for combating domestic terrorism, such as the Capitol Police, Secret Service, DHS, FBI, and Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF). Further resources have been directed toward improving residential security of lawmakers, providing larger security details for high-profile members of Congress and political candidates, and safeguarding campaign and district offices outside of Washington, D.C.28 Similar efforts have been made to protect judges by shielding their personal information from public databases and increasing their security details.29 The sum of these efforts has been that while terrorist attacks against government targets have been on the rise recent years, the number of fatalities has not. Increased security measures have proven critical time and again in protecting government targets and should be considered essential to combating domestic terrorism.
Second, the U.S. government, alongside international partners and the private sector, should continue to aggressively counter individuals and groups that promote violence on digital platforms. Nearly all domestic terrorists rely on the internet and social media to learn violent tactics, communicate with like-minded individuals, and spread and ingest propaganda and disinformation. Policymakers should press digital platforms to remove content that promotes domestic terrorism and violates their terms of service, ensuring these online spaces do not become breeding grounds for violent ideologies that inspire lone-wolf actors. In an era of increased tensions over what level of content moderation is appropriate, identifying, reporting, and removing offenders inciting or threatening to engage in violence should be a bipartisan issue.
Third, it is imperative that the U.S. government, political candidates, and media stakeholders communicate transparently about election integrity and limit misinformation and disinformation that risk inspiring violence. Conspiracy theories-particularly election denialism-are a primary cause of the recent increase in terrorist attacks and plots against government targets based on partisan political views. Failure to address these falsehoods not only erodes public trust in democratic institutions but also empowers extremist actors to justify violent actions under the guise of patriotism. As the United States prepares for the 2024 elections, these efforts are especially necessary.
Fourth, the U.S. government should strengthen its existing systems that are triggered in the event of a successful mass-causality or high-profile attack. Although terrorist attacks against government targets have been largely unsuccessful in large part due to security measures, there have also been several close calls that suggest a highly lethal event is still possible. For example, the response of police officers during the 2017 shooting at a congressional baseball practice targeting Republican lawmakers undoubtedly saved many lives.31 However, it was also to some extent a matter of luck that those shot at the practice were not killed.32 This event and others like it emphasize the need not only for increased security measures, but also for a review of existing protocols in the event of a successful attack. For example, one bipartisan group in the House of Representatives is pushing for a constitutional amendment that would allow members to be replaced quickly in the event of a mass-casualty event.33 Similar efforts to plan for such contingencies can disincentivize terrorist attacks against government targets, ensure stability in governance during crises, and improve public trust in democratic institutions.
Despite worrying data trends, there is cause for hope. Over the past several years, various federal agencies have increasingly prioritized research-driven approaches to understanding the scope and root causes of domestic extremism, allowing for more informed and targeted counterterrorism efforts.34 This has been paired with advancements in technology and data analysis, enabling law enforcement to detect and disrupt potential threats more efficiently.35 Policymakers now need to find ways to collaborate to reverse the rising domestic terrorist threat against government targets.
Riley McCabe is a program manager and research associate at the Warfare, Irregular Threats, and Terrorism Program at CSIS.
The author gives special thanks to Daniel Byman, Seamus Hughes, and Alexander Palmer for their review of the document. Thanks also to Jamie Landy, Skyeler Jackson, and Christina Nordby for their invaluable research assistance. Finally, thanks to Mayank Munjal for data visualization, Lauren Bailey for graphic design and layout, and Phillip Meylan for publications support.
For an overview of the methodology used in compiling the data set, please see here.
This brief was made possible through general support to CSIS. No direct sponsorship contributed to this brief.
Please consult the PDF for references.
CSIS Briefs are produced by the Center for Strategic and International Studies (CSIS), a private, tax-exempt institution focusing on international public policy issues. Its research is nonpartisan and nonproprietary. CSIS does not take specific policy positions. Accordingly, all views, positions, and conclusions expressed in this publication should be understood to be solely those of the author(s).
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