EVERYONE is talking about one man in Tanzania's first multiparty elections - and he isn't even running for office. That man is former President Julius Kambarage Nyerere, even though he officially retired 10 years ago. Many see Mr. Nyerere as one of the great elder statesmen of Africa; he assumed the role for decades of socialist pioneer and mentor to other liberation fighters on the continent. Stadiums, boulevards, and children have borne his name, including a son of former Zambian President Kenneth Kaunda. It seemed Nyerere would give up politics in 1990, when he left the helm of Chama Cha Mapinduzi (CCM, or Party of the Revolution), his ex-Marxist party that has ruled this East African country since independence more than 30 years ago. But he still conducts himself as the ''father of the nation'' - or Baba wa Tarifa, the title commonly used to refer to him. He has come out from the political shadows at his Butiama village retreat at Lake Victoria to influence events, candidates, and issues in the October elections. Like a traditional village elder, he speaks when he feels passionate about an issue. And he feels very passionate about these elections, influencing his party to endorse his chosen candidate and publicly attacking top officials who displease him. ''He may be officially retired from politics, but [he] is still very much on the scene,'' says a senior CCM official. The white-haired Nyerere also goes by the title Mwalimu, or teacher, and he adopts a lecturing tone when irked. His pronouncements are carried by the press as though he were still in charge. NYERERE became involved in party wrangling to ensure his former secondary-school student, current Science and Technology Minister Benjamin Mkapa, was chosen as the CCM's presidential candidate. The modern-day kingmaker can still ruin the careers of politicians who irritate him, such as former Premier John Malecela, who stepped down in November. Over the past year Nyerere has jumped with relish into a debate on the 31-year union between the mainland republic of Tanganyika and the island of Zanzibar, which together make up the United Republic of Tanzania. He has said he would not allow this union to fall apart. He successfully prevented the CCM from implementing a parliamentary resolution on the formation of a separate government for Tanganyika, calling on CCM members to resign if they favored the idea. ''They listen to him. He is still seen as the father of the country,'' says one Western diplomat. Nyerere's political activities are not welcomed by those who opposed his government's dogmatism and Soviet-style repression of free speech. He was among the most doctrinaire of African leftist leaders and based his economic policies on a Chinese Maoist model. The experiment ruined the economy, yet Nyerere has watched with dismay as orthodox socialism has unraveled under current President Ali Hassan Mwinyi. By putting the blame for harsh austerity measures and corruption on President Mwinyi, the charismatic Nyerere remains a drawing card for the CCM, as even opposition parties concede. ''Many people identify the CCM with Nyerere,'' says Seif Sharif Hamad, deputy chairman of the rival Civic United Front party. ''It is 10 years since he retired, but there are people who do not know that.''