are often viewed as being similar to anarchism due to similar criticisms of Leninist ideologies for being authoritarian and the rejection of the idea of a vanguard party. Trotskyism Trotskyism is the branch as advocated by Russian Marxist Leon Trotsky, a contemporary of Lenin from the early years of the Russian Social Democratic Labour Party, where he led a small trend in competition with both Lenin's Bolsheviks and the Mensheviks. Opposed to Stalinism, Trotskyism supports the theory of permanent revolution and world revolution instead of the two stage theory and socialism in one country. It supported proletarian internationalism and another communist revolution in the Soviet Union which Trotsky claimed had become a degenerated worker's state under the leadership of Stalin in which class relations had re-emerged in a new form, rather than the dictatorship of the proletariat. Struggling against Stalin for power in the Soviet Union, Trotsky and his supporters organized into the Left Opposition and their platform became known as Trotskyism. Stalin eventually succeeded in gaining control of the Soviet regime and Trotskyist attempts to remove Stalin from power resulted in Trotsky's exile from the Soviet Union in 1929. While in exile, Trotsky continued his campaign against Stalin, founding in 1938 the Fourth International, a Trotskyist rival to the Communist International. In August 1940, Trotsky was assassinated in Mexico City on Stalin's orders. Trotsky's followers claim to be the heirs of Lenin in the same way that mainstream Marxist–Leninists do. There are several distinguishing characteristics of this school of thought—foremost is the theory of permanent revolution. This stated that in less-developed countries the bourgeoisie were too weak to lead their own bourgeois-democratic revolutions. Due to this weakness, it fell to the proletariat to carry out the bourgeois revolution. With power in its hands, the proletariat would then continue this revolution permanently, transforming it from a national bourgeois revolution to a socialist international revolution. Another shared characteristic between Trotskyists is a variety of theoretical justifications for their negative appraisal of the post-Lenin Soviet Union after Trotsky was expelled by a majority vote from the All-Union Communist Party (Bolsheviks) and subsequently from the Soviet Union. As a consequence, Trotsky defined the Soviet Union under Stalin as a planned economy ruled over by a bureaucratic caste. Trotsky advocated overthrowing the government of the Soviet Union after he was expelled from it. Marxism–Leninism Marxism–Leninism is a political ideology developed by Joseph Stalin which