During the Cold War, communist parties in many nations emulated a structure copied from the organisation of the Communist Party of the Soviet Union as designed by Vladimir Lenin. In theory a party congress would elect a central committee[?], which elected a Politburo. In practice, the Politburo was self perpetuating and tended to control the central committee which controlled the party congresses. In most nations where communist parties gained power, opposition parties were banned or assimilated into socialist fronts.
Members of communist parties were often persecuted in the early Cold War hysteria which swept through much of the West following World War II, especially in the United States. US Senator Joseph McCarthy claimed to have a long list of secret communists who were holding posts in the United States government, and was appointed chairman of the Permanent Investigating Subcommittee of the Senate Committee on Government Operations.
McCarthy subpoenaed numerous government officials, Hollywood producers and stars, politicians, and others, and grilled them at televised hearings on what connections, if any, they had with communist organizations. More and more people increasingly characterized the effort as a witch hunt, and many successful careers were destroyed by allegations of being a communist spy which ultimately proved completely baseless. The hysteria abated somewhat when McCarthy accused several high level members of the US Army of being communists, and Army lawyer Joseph Welch publicly denounced McCarthy during a hearing by asking him, "Have you no sense of decency, sir, at long last? Have you no sense of decency?"
Communist parties also gained strong electoral and organisational support in France and in Italy, where they and developed a variant ideology known as Eurocommunism. While these parties advocated radical restructuring of the economy, they also eventually accepted the legitimacy of multi-party elections.
Communists parties around the world have mostly disappeared after the fall of the Berlin Wall. However, in Brazil at least, different parties claimed (or claim yet) to be communist, each according to its own version of communism.