When I came of age during the 1950s, liberals and civil libertarians were deeply concerned about the abuses of congressional investigations to expose communists and “fellow travelers.” Republican Senator Joseph McCarthy was using congressional committees to do his dirty work. The committee leaders would claim that they had legitimate legislative purposes in subpoenaing actors, professors, and government employees to interrogate them about their past political affiliations. The purported purposes were to legislate more effective controls over communist influence in our government and to conduct oversight of the executive branch. Most liberals and civil libertarians saw through this ruse. The obvious...