ON Sunday, voters in this former Soviet republic of 53 million people will decide in a referendum whether another fledgling democracy, the Ukraine, will appear on the eastern edge of the changing map of Europe.The fate of the former Soviet Union rests largely on this vote and its political consequences. Prospects for a continued political union depend on the participation of the Ukraine, the second most populous and wealthiest of the 12 former Soviet republics. At this point, based on polls and sources here, few doubt that a large majority of the Ukrainian populace will vote for independence. Reflecting that likelihood, an adviser to President Mikhail Gorbachev, Georgy Shaknazarov expressed the hope this week that a "declaration of independence will not prevent the Ukraine from participating sooner or later in the union." Less certain, however, is the outcome of the Ukraine's first presidential election, also scheduled for Sunday. (Ukrainians speak out on vote, page 7.) The six candidates still in the race reflect the range of political and social forces that have developed over the last six years of perestroika in a republic once known as a reservation for hard-line Communists. Despite their backgrounds, all six men have championed independence and share similar platforms. As expected, the front-runner in the polls is the highly visible chairman of the Ukraine's parliament and former Communist Party ideologue, Leonid Kravchuk. His closest challenger is Vyacheslav Chernovil, a lifelong dissident and former political prisoner, who is supported by the Ukrainian nationalist movement Rukh. Unhindered by his 30-year career rising through the party ranks, Mr. Kravchuk has positioned himself comfortably at the top, skillfully balancing political forces in his favor. On a recent campaign stop in Uzhorod, in the Ukraine's Carpathian Mountain region, Kravchuk explained his definition of a successful politician. "I find it is always the case that the direction a politician follows is determined by the positioning of political forces in the society," said Kravchuk. "Today these forces in Ukraine are polarized. A politician must take into account this force and that force, and listen to one and the other, and on that basis come to a conclusion. If he takes only one side, then he necessarily loses," said Kravchuk. "He's really the Teflon man. He's able to weather potentially tight spots and can slide off tough questions. He's very smooth and dynamic, and he's good on TV," said John Hewko, a consultant to the Ukrainian parliament. And Kravchuk has been successful in usurping much of the nationalist programs of his rivals. Both the leading candidates advocate full democracy, a free market, privatization of property, equal rights for national minorities, a national army and currency, and a nuclear-free state. Kravchuk has become a strong advocate of Ukrainian independence, firmly opposing the republic's participation in any renewed political union. Although the Ukraine has signed the treaty to form an economic community, in a press conference Tuesday Kravchuk dismissed the treaty as "an illusion." Kravchuk's Rukh opponents have tried to exploit concerns about his Communist past and especially his silence during the first days of the attempted hard-line coup in August. "One should fear any president who is not firm, who changes his views the way he changes his gloves," said Les Taniuk, a popular deputy from the Ukrainian legislature's democratic bloc and a vocal Chernovil supporter. "Yes, I made some mistakes in those days. Those were different times," Kravchuk said in a TV appearance in Uzhorod. "Since I became chairman of the Supreme Soviet last year, I partially stepped aside from the work of the Central Committee of the Communist Party of the Ukraine. During the August coup, when one had only minutes and not hours to act, my thoughts were occupied by something else at the time - how to preserve peace and quiet and prevent any innocent bloodshed. That was the main thing. I consid er quitting the party a private and delicate matter." Some voters are skeptical of such labored explanations. "I say he's very clever and cunning, like a fox," said a young film director in Kiev. However the most recent polls show the strength of Kravchuk's appeal. A poll of 2,600 people conducted between Nov. 10 and 15 by Kiev State University for the Ukrainian parliament indicated that 51 percent preferred Kravchuk of all the candidates. Mr. Chernovil received a rating of 19.2 percent. Rukh organizers are hoping to keep Kravchuk under 50 percent in order to force a runoff election between the two top finishers. In his brief encounters with voters during his visit to Uzhorod and a nearby mountain village, Kravchuk displayed an approachability and rapport of a Western-style politician. "You're such an attractive man in person," shouted one village woman." When asked by several women in front of the village church whether he believed in God, Kravchuk replied: "Yes, I'm a believer. I believe in truth. I believe in a great idea. I believe that an individual is the highest being and nothing stands above him."