This is a very interesting interview with John Earl Haynes and Harvey Klehr, authors of "In Denial: Historians, Communism, and Espionage" (2003). Worth reading the whole, but here is a tidbit: "At Solovki, one of earliest Gulag camps, Soviet administrators put up a sign that expressed the Communist program: With an Iron Fist, We Will Lead Humanity to Happiness. That slogan captures the murderous nature of the utopian vision of the hard left.
Jamie, you look at Soviet history and see the Gulag, the executions of the Terror, the pervasive oppression, and the economic failure. Psychologically, the leftists you speak of see little of that. They see a Communist state that articulated their vision of the future and which sought to destroy the societies and institutions they hated. They cannot see the horror that communism actually created. They look on that horror and see something else because they cannot admit to themselves that their vision is beyond human grasp. The German Communist playwright Bertolt Brecht, when challenged that thousands of innocents had been sent to the Gulag by Stalin, replied, the more innocent they are, the more they deserve to die. To you or I this remark is disgusting, but to the hard left it reflects their eager willingness to kill any number of persons without concern for innocence or guilt if it might assist in bringing about the socialist future."