Yuri N. Afanasyev, a Russian historian and former Communist loyalist who became a leading democratic politician in the late Soviet era ...died Sept. 14. He was 81. In 1989, Mr. Afanasyev helped found Memorial, an organization dedicated to exposing Stalin’s atrocities and commemorating the victims. That year he also joined the Soviet Union’s first freely elected parliamentary body, the Congress of People’s Deputies, which was created under Mr. Gorbachev’s reforms. But he grew disenchanted, doubting that its unwieldy mix of Stalinists, democrats and Communist Party functionaries could bring about change, and denouncing both its “aggressively obedient majority” and Mr. Gorbachev....