BREAKUP OF THE SOVIET UNION : Bush Administration Applauds Gorbachev’s ‘Virtuoso Performance’ : Reaction: ‘Some people . . . thought he had run out of both hats and rabbits. He turned out to have both,’ an official says.

Only a week after fearing that Mikhail S. Gorbachev might be swept from office, advisers to President Bush have concluded with amazement that he has forged a new base of support and will hold on to real power in the government now emerging in Moscow, senior officials said Friday.

The Administration experts expressed surprise and relief at what one called a “virtuoso performance,” which carried Gorbachev from humiliation to new stature in a matter of days.

In a week that saw the old Soviet Union fade into history, Gorbachev deftly maneuvered to seize a role as a voice for those who fear new domination by Russia, the Administration experts said.

This “fairly stable” base of support among leaders of Asian and other non-Slavic republics is now likely to provide Gorbachev new room to function and to counter the excesses of Russian Federation President Boris N. Yeltsin, the officials predicted.

“Some people in government and out thought he had run out of both hats and rabbits,” conceded a senior Administration official, accounting for the recent pessimism about the Soviet leader. “He turned out to have both.”

What the officials called a remarkable renaissance by Gorbachev is seen as an important benefit as the United States begins to overhaul a foreign policy that had focused on a unified Soviet state.

In an Administration that places great stock in personal diplomacy, the constancy secured by Gorbachev’s return from irrelevance guarantees at least for now that the Soviet leadership will include a man with whom the White House can deal and already knows well.

“Many political leaders would not have been able to rebound from the press conference and the humiliation before the Supreme Soviet,” one senior Administration official said in apparent awe at the Gorbachev recovery.

The government expert was referring to the Soviet leader’s disastrous first public appearance after the failure of last month’s putsch, at which he defended the Communist Party, and to an incident a day later when Yeltsin flexed his new muscle by shaking a finger at Gorbachev as they stood before the legislative body.

But offering a new image that officials said was emblematic of his resurgence, Gorbachev twice Thursday night contradicted Yeltsin as the two appeared together on American television. While cordial on the surface, the tactic appeared designed to show that the two were once again on equal footing.

A senior official said Friday the Administration believes that Yeltsin may have “flirted with the idea” in the first days after the failure of the coup that he could cast Gorbachev aside and exert power over the Soviet republics.

But the official said that Yeltsin’s plan appeared to have been set back as first the Ukraine and then Kazakhstan, the most powerful republics apart from Russia, made clear that they would not submit to such Russian domination.

Experts said that setback provided an opening for Gorbachev, as leaders of the Ukraine, Kazakhstan and others embraced his dramatic plan to give equal voice to each of the Soviet republics.

“They’ve got Gorbachev, who seems to understand their needs, and they have a union which seems to dilute Russian influence,” a senior Administration official said of the Soviet leader’s new base of support outside the Russian Federation.

The apparent return of Gorbachev to a position of power is regarded as particularly important among those close to Bush who have harbored doubts about Yeltsin and his long-term agenda.

Yet in expressing relief at Gorbachev’s resurgence, senior officials stressed that the Administration is beginning to warm to Yeltsin. In recent pronouncements supporting Baltic independence and opposing aid to Cuba and Afghanistan, one aide said, Yeltsin could well have been repeating the “talking points” of U.S. foreign policy.

At the same time, U.S. officials cautioned that it remains unclear whether Gorbachev can ever recover the mass popularity necessary to win a popular election, which the Soviet Union had promised to hold next year.

And while they described his new base of support as stable, they acknowledged that the unleashing of popular passions in the republics as well as in Moscow could present Gorbachev’s new allies with political problems that could make their own tenures uncertain.

For political leaders who have long heeded only Moscow, one official said, the sudden upheaval means that “politics is going to mean looking out the window, not just listening to the telephone.”