WHEN Yuri Pines was a schoolboy in the Soviet Union, his classmates used to ask him whether it was true that as a Jew he was not meant to eat pork.He rebuked them for believing anti-Semitic propaganda, he recalls today with a smile. "I knew no more about being Jewish than they did." To many Israelis, the most striking aspect of the current wave of Soviet immigration is not so much its overwhelming size, as the scale of the immigrants' ignorance of Jewish traditions. With Soviet Jews likely to make up one-fifth of Israel's population by 1995, the implications of this for society are enormous. And as sociologists seek to divine future trends, politicians are engaged in the more immediate task of winning new votes. On the face of it, the 1 million Soviet immigrants expected to arrive here should enjoy decisive clout. At the next elections, due by November 1992, Soviet Jews will command enough votes to elect seven members of the 120-member Knesset. But for a variety of reasons, analysts predict, the new immigrants will not fully exert their potential political influence. They cite several hindrances: a lack of social cohesion among the various groups of ethnic Jews in the Soviet Union; almost total inexperience in t he tactics of political organizing; and an unfamiliarity with the traditions and lore of Judaism. For more than 70 years, since the Russian Revolution, the Soviet Union's estimated 3.5 million Jews have been cut off from Jewish traditions. "Except for a few phrases of Yiddish, the average Soviet Jew knows nothing of Jewish life, nothing of Judaism, nothing of the philosophy or history," says Ze'ev Freiman, himself an "average Soviet Jew," until he started exploring his roots in the mid-1980s. But few of his compatriots shared Mr. Freiman's curiosity. A recent poll by the Institute for Secular-Humanistic Judaism found that only 3 percent of the new Soviet immigrants describe themselves as religious, 16 percent as "traditional," and 81 percent as "nonreligious." Not many of the newcomers are particularly strong believers in the state of Israel either. "The main reason they are leaving is that they are simply afraid of living in the Soviet Union," where political and economic dissolution loom, says Roza Finkelberg, who runs activities in the Soviet Union for the Soviet Jewry Zionist Forum, an immigrant rights group. "And the doors are closed to them everywhere else." The restrictions on Jewish community life in the Soviet Union, and the fact that few Jews there live together in distinct neighborhoods that would forge a common bond, are also expected to impede efforts to organize the new immigrants. "They didn't know anything about each other except as Russians," points out Ze'ev Chafets, editor of the weekly Jerusalem Report. "So it's hard to get a good fix on them as a group." Indicative of this dispersion is the lack of any agreed leader, as the idea of forming a political party for the Soviet Jews floats around Jerusalem. A poll by the Tazpit Institute found former Soviet refusenik Natan Scharansky to be the most widely recognized figure among the immigrants. But even he was mentioned by only 9 percent of respondents. "A Russian political party would have a temporary chance, but there wouldn't be one, there would be five or six," says Mr. Pines, who arrived from the Soviet Union as a boy in the 1970s. "The votes would be dispersed, so they won't be a real factor." More likely, says Tazpit director Aaron Fein, the dominant Likud and Labour parties "will follow the past pattern of getting a leader of new immigrant groups into [their] party to bring votes." On this front, Labour leader Shimon Peres is taking highly publicized Russian-language classes, and the Labour movement through its trade unions and grassroots committees is making a serious effort to attract the Soviet vote. Likud, on the other hand, appears to be banking on the assumption that new immigrants are naturally grateful to the government that helps them and that, as runaways from the Soviet Union, they are naturally hostile to left-wing parties. The Likud chairman of the Knesset Aliyah and Absorption Committee, Mikhail Kleiner, however, warns against overestimating immigrant backing. "If the immigrants feel that absorption is a failure they will vote for the opposition," he says. Set apart from previous waves of immigrants by their lack of religious or political motivation, the Soviet Jews pose a very particular problem for Israelis anxious to integrate them into society. "These people are typical specimens of 'homo Sovieticus, says Eduard Kuznetsov, editor of the Russian-language daily, Vremya. "They have an ability to survive, but they are not motivated by any ideas, and because they are not motivated they do not understand that they have to change themselves. For these people it will be very hard to adapt." Mr. Kuznetsov fears that large numbers of the new immigrants "will never become an integral part of the state but will exist somehow on the margins, obedient to the rules, but dreaming of going somewhere else." Should the practical problems of absorbtion prove unmanageable, however, some officials predict more dramatic changes. "What will Israeli society look like in 20 years?" wonders Jewish Agency aliyah chief Uri Gordon. "If we don't find real existential answers to the problems, it might undermine the fabric of our society." Literature professor Roman Timenshik, recently arrived from Riga, has similar fears. "I am afraid of a social conflict that will take on the colors of a cultural conflict and even of a national conflict" between Soviet Jews and veteran Israelis, he says. "The government seems blind to this possibility," he adds. "Perhaps to the local Israeli population the idea of conflicts between Jews is too strange." Even those veteran Israelis who lament the newcomers' lack of Jewish identity, however, are confident that things will work out in the end. "It's true they know nothing of Judaism, they are not Zionists, they come here only because they could go nowhere else," acknowledges Nitza Ben Zvi, a senior official in the Ministry of Labour. "But their children will go to school, and they will soon be no different from our children." Uri Gordon too puts his trust in the next generation. "This country is open to all Jews," he says. "The ones coming now are not Zionists, but their children will be good Jews, good Israelis, and good Zionists."