The notable Soviet politician known for his denunciation of Stalin's crimes is Leon Trotsky. A prominent figure in the Russian Revolution, Trotsky initially supported the Bolshevik regime. However, he later became an outspoken critic of Stalin's leadership and policies, particularly regarding political repression and the purges. His 1936 work, "The Revolution Betrayed," highlights his perspective on the distortion of Marxist ideals under Stalin's rule. Trotsky's opposition to totalitarianism and advocacy for international socialist revolution remains significant in discussions of Marxism and Soviet history.