Formerly a derogatory term used by V.I. Lenin in “Left-Wing” Communism: an Infantile Disorder, Left-Wing Communists are critics of the Bolshevik party and their 1917 Revolution, who still proclaim to be philosophically Marxist.
Amedeo Bordiga was the Leader of the Italian Communist Party, and generally considered by leftists to be one of the most prominent thinkers in Left-Wing Communism. He criticized the Bolshevik party for being far too Capitalistic and Democratic. Though Marx himself made no direct opposition to the idea of majority control, Bordiga insists on Organic centralism, which he describes as a party which will ensure "maximum possible consultation with the base". To most other Communists, this comes off as a failure to recognize the distinction between Democracy (in its abstract philosophical form) and physically voting with ballots.
Though subject to right-wing conspiracy theory and represented as a Zionist-funded think tank meant to advocate cultural subversion and "degeneracy", the Frankfurt School is actually a philosophy that specializes in Hegelian-Marxist social theory. Leaders such as Theodor W. Adorno opposed many cultural elements of the Weimar Republic, which he himself viewed as subversive and anti-Marxist, such as the popularization of jazz music. Advocates of the Frankfurt School in Germany heavily criticized both the Soviet Union and Weimar Republic in their time, and chose to aid the OSS with the outbreak of World War 2