Babrak Karmal befriended fellow inmate Mir Akbar Khyber, who introduced Karmal to Marxism. Karmal changed his name from Sultan Hussein to Babrak Karmal, which means "Comrade of the Workers'" in Pashtun, to disassociate himself from his bourgeois background. When he was released from prison, he continued his activities in the student union, and began to promote Marxism. Karmal spent the rest of the 1950s and the early 1960s becoming involved with Marxist organizations, of which there were at least four in Afghanistan at the time; two of the four were established by Karmal. When the 1964 Afghan Provisional Constitution, which legalised the
Babrak Karmal and a half days of a 3-day long program, because of the inter-party struggle for power between the Khalqists and the Parchamites. A "program of action" was introduced, and party rules were given minor changes. As an explanation of the low party membership, the official media also made it seem hard to become a member of the party. When Karmal took power, he began expanding the support base of the PDPA. Karmal tried to persuade certain groups, which had been referred to class enemies of the revolution during Taraki and Amin's rule, to support the PDPA. Karmal appointed several non-communists