ANC, Mandela and his party cadre allies began advocating direct action against apartheid, such as boycotts and strikes, influenced by the tactics already employed by South Africa's Indian community. Xuma did not support these measures and was removed from the presidency in a vote of no confidence, replaced by James Moroka and a more militant executive committee containing Sisulu, Mda, Tambo and Godfrey Pitje. Mandela later related that he and his colleagues had "guided the ANC to a more radical and revolutionary path." Having devoted his time to politics, Mandela failed his final year at Witwatersrand three times; he was ultimately denied his degree in December 1949. Defiance Campaign and Transvaal ANC Presidency: 1950–1954 Mandela took Xuma's place on the ANC national executive in March 1950, and that same year was elected national president of the ANCYL. In March, the Defend Free Speech Convention was held in Johannesburg, bringing together African, Indian and communist activists to call a May Day general strike in protest against apartheid and white minority rule. Mandela opposed the strike because it was multi-racial and not ANC-led, but a majority of black workers took part, resulting in increased police repression and the introduction of the Suppression of Communism Act, 1950, affecting the actions of all protest groups. At the ANC national conference of December 1951, he continued arguing against a racially united front, but was outvoted. Thereafter, Mandela rejected Lembede's Africanism and embraced the idea of a multi-racial front against apartheid. Influenced by friends like Moses Kotane and by the Soviet Union's support for wars of national liberation, his mistrust of communism broke down and he began reading literature by Karl Marx, Vladimir Lenin, and Mao Zedong, eventually embracing the Marxist philosophy of dialectical materialism. Commenting on communism, he later stated that he "found [himself] strongly drawn to the idea of a classless society which, to [his] mind, was similar to traditional African culture where life was shared and communal." In April 1952, Mandela began work at the H.M. Basner law firm, which was owned by a communist, although his increasing commitment to work and activism meant he spent less time with his family. In 1952, the ANC began preparation for a joint Defiance Campaign against apartheid with Indian and communist groups, founding a National Voluntary Board to recruit volunteers. The campaign was designed to follow the path of nonviolent resistance influenced by Mahatma Gandhi; some