In some political contexts the term fellow traveler refers to a person who sympathizes with the beliefs of a particular organization, but does not belong to that organization. The phrase must be understood as referring to people who "walk part of the way" with an organization, without committing themselves to it. Since the Russian Revolution and rise of the Communist Party in the Soviet Union, the term has most often been used for a sympathizer of Communism or particular Communist states, but who is nonetheless not a "card-carrying member" of a Communist party.
Between bourgeois art, which is wasting away either in repetitions or in silences, and the new art which is as yet unborn, there is being created a transitional art which is more or less organically connected with the Revolution, but which is not at the same time the art of the Revolution. Boris Pilnyak, Vsevolod Ivanov, Nicolai Tikhonov, the “Serapion Fraternity”, Yessenin and his group of Imagists and, to some extent, Kliuev – all of them were impossible without the Revolution, either as a group, or separately. ... They are not the artists of the proletarian Revolution, but her artist “fellow-travellers”, in the sense in which this word was used by the old Socialists. ... As regards a “fellow-traveller”, the question always comes up – how far will he go? This question cannot be answered in advance, not even approximately. The solution of it depends not so much on the personal qualities of this or that “fellow-traveller”, but mainly on the objective trend of things during the coming decade.During the relatively open era of the New Economic Policy in the Soviet Union, some writers were able to write on subjects as they chose. During the following periods of repression, particularly after the ascendancy of Joseph Stalin and his widespread Great Purge, many intellectuals found their positions difficult. Writers as well as millions of political activists, teachers, farmers and ordinary people were arrested and sent to labor camps in Siberia, where many perished. Some writers emigrated when the authorities refused to allow publication of anti-regime works, while others ceased writing altogether, sometimes under coercion.
Many French and American journalists, intellectuals and artists in the 1930s and 1940s were described (and sometimes referred to themselves) as fellow travelers, including André Gide, André Malraux, Romain Rolland, Jean-Paul Sartre, Ernest Hemingway, and Martha Gellhorn.
As in Europe, in the 1920s and 1930s numerous American intellectuals sympathized or joined the Communist Party in the United States as young activists. In part this also reflected people's search for answers to social problems during the drastic dislocations of the Great Depression and Dust Bowl years, when the inequities of American society seemed overwhelming. As more information came out about government and Party activities in the Soviet Union, many of those people left the party in the United States.
From the 1940s on, membership in communism was in decline in the United States. Information about widespread purges and the show trials by Stalin as leader of the Soviet Union, and further shocking revelations about the crimes of his regime after his death, caused many adherents to rethink their commitments.
Because of political controversies surrounding the subject as a result of the McCarthy hearings in the 1950s, the term in this context and since then was often used as or considered to be a political pejorative. People were blacklisted on suspicion of Communist sympathies, even when their active affiliation was decades in the past.
Soviet aggressions against Hungary in 1956 and Czechoslovakia in 1968 had a similar effect. Discovery of Soviet funding of the CPUSA operating costs and espionage activity spread further disillusionment. In 1991, the party purged several hundred party members who had called for reform at the CPUSA's 25th national convention in Cleveland. It has not been a force on the left for some time.
In his 1958 book, Hoover defined a "fellow traveler" as one of five types of dangerous subversives. He believed any of them might promote the goal of a Communist overthrow of the United States government. The five types were:
While the card-carrying Communist was known as a 'Red', Hoover called the Communist sympathizer, the Underground Communist and the Dupe a 'Pink' or 'Pinko.'