"AI OverviewAnalyses from government agencies and independent research groups indicate that white supremacists and other right-wing extremists are responsible for the majority of lethal domestic terrorism in the U.S. in recent years. Dominant threatRight-wing extremist violence has caused a significant percentage of domestic terrorism deaths since 2001, with some analyses placing the figure as high as 75% to 80%. White supremacists have been responsible for a large portion of fatalities within right-wing extremist attacks. Both the Department of Homeland Security and the Federal Bureau of Investigation have identified white supremacist violence as the "most persistent and lethal terrorist threat to the homeland". White supremacist violence remains a top counterterrorism concern, and data shows it has been more frequent and deadlier than violence from left-wing extremists.