NEWS ANALYSIS : Yeltsin’s Decisive Victory Bolsters Gorbachev’s Hand : Politics: The Russian Federation election indicates that Soviet conservatives are too weak to block reform.

As final returns come from the remote corners of the Russian Federation to confirm Boris N. Yeltsin’s victory in its first presidential elections, another, hidden winner is emerging--Mikhail S. Gorbachev, the Soviet president.

The conventional political wisdom here held that the bigger Yeltsin’s victory--and confirmed results give him more than 57% of the vote against five opponents--the stronger he would be as a rival to Gorbachev on the national scene.

But so decisively did Yeltsin defeat the conservatives that they now appear incapable of mounting the same threat to Gorbachev and his reform program as they have over the past three years. The election results expose the conservatives as lacking real popular support.

Looking beyond the election, Gorbachev advisers see clear gains for the Soviet president in Yeltsin’s unambiguous victory:

* Gorbachev now has an ally with a clear mandate for radical political and economic reform, including development of a mixed, market economy, reduction of the country’s massive military-industrial complex and the privatization of state-owned enterprises, all of which Gorbachev proposed two and three years ago.

While Yeltsin will probably want to go further and faster than Gorbachev, they are proceeding in the same direction and are secure enough to make the difficult decisions that lie ahead, according to Soviet political observers. Differences between Gorbachev and Yeltsin have largely been about the speed and scope of change, and the last three months have brought them closer together.

* Yeltsin will be as anxious as Gorbachev to conclude the prolonged discussions on a new Union Treaty, meant to be the political basis for the reconstitution of the Soviet Union as a federal state. As the president of the largest Soviet republic, Yeltsin is seen as committed to the Soviet Union’s continuation rather than its breakup.

Even as the votes were counted last week, however, Gorbachev had become a clear and unexpected winner.

The conservatives, who have been the principal threat to perestroika, as Gorbachev’s program of political and economic reforms is known, were vanquished in the election, and a potential ally, Yeltsin, won a commanding position in the political center that protects Gorbachev from both conservatives and radicals.

The Soviet president, while noting the complexities of Russian politics in a weekend television interview, was pleased with the election results. Recounting a telephone conversation with Yeltsin, Gorbachev said: “We had a short, positive conversation. We agreed to act together and to continue the cooperation that emerged in recent days, and we are going to expand it.”

And thus the Gorbachev-Yeltsin alliance of the past two months was confirmed.

“There’s no doubt that the conservative dragon has been slain,” a Gorbachev aide said over the weekend. “The threat that, if we did this or that radical thing, the conservatives would rise up and devour us is gone. . . . When they faced the electorate, the conservatives turned out to be a paper dragon.”

Nikolai I. Ryzhkov, the former Soviet prime minister, who ran as the candidate of the conservative Russian Communist Party, failed to get even 20% of the vote. According to the confirmed returns Sunday from 67 of Russia’s 88 electoral regions, he received only 17%, winning just in a few remote areas.

Only last autumn, the powerful military-industrial complex had used Ryzhkov to force Gorbachev to abandon the radical “500 Day” program of economic reform--in effect a forced march to the market economy--that he had endorsed a month earlier.

Col. Gen. Albert M. Makashov, the nominee of the hard-right ultra-conservatives, who pushed for a return to the old verities of Marxism-Leninism and showed considerable nostalgia for the dictator Josef Stalin, won only 3.6% of the vote.

Even in military units, Makashov’s percentage was not much greater, suggesting that he might have the vote of the colonels but that the majors, captains, lieutenants and sergeants had largely rejected his demand for a Stalinist return to order, discipline and communism. In other words, the Soviet military is neither monolithic nor Stalinist.

From last autumn through the winter, however, suggestions that the military and the party’s hard-right might mount a coup d’etat had imposed severe political constraints on Gorbachev, who found himself lavishing honors on generals he wanted to fire and biting back on reforms he knew he should undertake.

And then there was the final surprise: Vadim V. Bakatin, an attractive candidate from the Communist Party’s liberal wing who, as a Gorbachev adviser, presumably ran with the president’s blessing, did no better than Makashov, winning only 3.5% of the votes cast.

“The people have rejected the party, completely and unequivocally, and that frees Gorbachev to be Gorbachev,” a political commentator on Radio Moscow said Sunday.

“Whatever fear Mikhail Gorbachev might have had of the party, of the conservatives, of the right wing, of the military and so on should have died with the election returns from (the cities of) Vladivostok, Irkutsk, Novosibirsk and Kursk. They did their best, and they were beaten, and badly beaten.”

Were there any doubt about the implications of the vote, it was resolved by the showing of Vladimir V. Zhirinovsky, chairman of the tiny Liberal Democratic Party, who with a promise of freely available vodka captured nearly 8% of the vote--without a further political stand and without any political organization.

“In this election, Mikhail Gorbachev was freed from having to worry about the views of the Communist Party, notably its hard-liners,” another of the president’s advisers said Sunday. “Gorbachev faced them down in the Central Committee in April, and Yeltsin has defeated them at the polls in June. What challenge could they mount now?”

Even the possibility, debated here widely over the winter, of a military takeover on behalf of the conservatives is rejected by those who had previously considered it a serious threat.

“Our generals are not so stupid that they would consider a coup when they know that they would have the support of no more than 20% of the people,” the adviser continued. “They have enough experience in occupation armies in Eastern Europe, in Afghanistan, in Africa and in Asia not to want to try it at home.”

From the outset, the Russian Communist Party believed that it would be able to force Yeltsin into a runoff election by denying him the 50% of the vote needed for an outright victory and that this embarrassment of such a popular leader would demonstrate its political strength.

In the party’s calculations, Ryzhkov and Bakatin were calculated to win 40% to 45% of the votes between them, and the other three candidates were expected to take at least 5% each, a total overall of 55% or 60%. In the actual vote, Ryzhkov, Bakatin and Makashov together won no more than a quarter of the ballots cast.

A final factor in the vote, most political observers believe, was the reconciliation in late April between Gorbachev and Yeltsin. Their feud, rooted as much in a severe personality clash as in real political differences, had gone too far, many felt, when Yeltsin in February called for a liberal “declaration of war” on Gorbachev.

“Yeltsin’s winning margin came from the reconciliation with Gorbachev,” a commentator in the independent newspaper Nezavisimaya Gazeta wrote.