Like containment, however, the exclusion strategy has pitfalls. Most important, it is a tool that is easily abused. American history is replete with instances of such abuse: the 1798 Alien and Sedition Acts; the imprisonment of the socialist leader Eugene Debs; the 1919–20 Palmer Raids; the notorious House Un-American Activities Committee and Senator Joseph McCarthy’s political witch hunts; and the surveillance, prosecution, and even killing of African American leaders and activists.
