MOSCOW -- The Soviet Union is entering an era of post-Gorbachevian politics. A generation of younger politicians, still itching in their new suits and ties, have become mayors, legislators and republican presidents and have widened the range of public debate. At times Mikhail Gorbachev reacts sharply to this new generation, scolding them like a father who feels his children have betrayed the limits of his tolerance.

The other night, a group of several of the best-known young legislators in the Congress of Peoples Deputies crowded around a television here and giggled and groaned and rolled their eyes as Gorbachev gave an impassioned speech defending socialism, the "Leninist conception" of the multi-national union and "the sacred choice of 1917."

"He just can't let the old stuff go," one of them said.

The Gorbachev who this week will meet with George Bush in Washington often appears more comfortable with people who are, in the end, his natural opponents. Deeply conservative figures in the Communist Party's Central Committee and in the Russian nationalist movement may do all they can to put the brakes on Gorbachev's westernizing reforms, but they do observe the old Soviet habit of deference to the leader. They make no noise on Red Square.They also tend to lose elections. For all of that, Gorbachev seems immensely grateful.

At some point -- perhaps somewhere between the liberation of Eastern Europe and the secession crisis in Lithuania -- Gorbachev lost pace with many of the forces he let thrive. The constituencies that were once his natural allies -- Moscow intellectuals, Baltic nationalists, the young -- are now in edgy competition, even conflict, with their mentor. They doubt Gorbachev's ability to thrive once more in the new world of multi-party politics he has helped create.

"Like any politician, no matter how great, Gorbachev is a product of his age and his political world -- the Communist Party. We are watching him hit the wall of his own limits," says Galina Staravoitova, a demographer and one of the young radicals who have won notoriety in the Soviet parliament. "Gorbachev resents anyone now who disagrees with him, and these are people who are at least as innovative in their thinking as he is. They are 'extremists' in his terms. That rejection is his tragedy as a politician, and ours as well."

In the West, we are accustomed to thinking of Soviet leaders in terms of decades. But under Gorbachev the evolution of politics and political thinking has accelerated to such a degree that Gorbachev's five years in power already represent an epoch, an epoch of radical, liberating change. The West still trains its attention and hopes on one man, but millions here are beginning to look to a wider range of names: Popov and Stankevich, Prunskiene and Lauristin, Sobchak and Chernovil.

The truth is, the headiest days of the Gorbachev Revolution are over. There is a nervous sense in the air and in the bones that the best the Soviet Union and its president can hope for in the next few years is a minimum of chaos and pain. At times the country now seems to have the collective psychology of a soldier walking through a mine field: it's impossible to celebrate the last step when safety always seems farther away.

The atmosphere within Gorbachev's own political world -- the Communist Party leadership -- is funereal. How best to manage the party's disintegration is the talk of the day. At a recent meeting of the party's Politburo, members discussed the possibility of calling for some kind of official party split, a well-informed party source said. Gorbachev's two closest allies in the Politburo, Eduard Shevardnadze and Alexander Yakovlev, supported a split, but the others voted against. Gorbachev himself said the party should stay together a while more.

Most of the old-guard party apparatchiks are either digging in for a long battle against their own ouster or they ape the lexicon and style of Gorbachev himself. Those who try to imitate Gorbachev usually end up looking pathetic, rather like dinosaurs dancing the Twist.

In the meantime, tens of thousands are quitting the party in disgust. Nikolai Travkin and Yuri Afanasyev are just two prominent radicals in the legislature to have given up on the drive to "reform from within." They handed in their party cards recently. Afanasyev is now a Social Democrat and Travkin has dismissed socialism entirely and is helping to begin the Democratic Party this weekend. Many more communists would quit the party if they were confident it would not hurt their careers.

There is something at once refreshing and discomfiting about watching the transformation of Gorbachev's status. The walls along Pushkin Square these days are plastered with little cartoons mocking Gorbachev for imperial ambitions and his self-professed insistence on remaining a communist. Several actors are now making careers out of imitating Gorbachev's southern accent and high-handed style. The other day the office fax machine here spit out a walloping attack on Gorbachev -- courtesy of the Democratic Union newspaper, The Free Word.

Gorbachev even gets slammed from time to time in the pages of Pravda. In a letter published in the party daily May 16, Olga Nikitivna Ischenko of Krivoi Rog, writes, "Dear Mikhail Sergeyevich . . . . Thanks to you, I have decided to give up my party card after 22 years of serving in the party ranks." The letter, a confused ramble, thanks Gorbachev for "awakening" the country to its failures and tragic history, but criticizes him for doing little to undercut the party apparatus. "We are disappointed in you," Ischenko writes. So why should all this pluralism feel vaguely dangerous? Muscovites and foreign reporters are perhaps too sensitive to the rumors and static electricity of a given political moment, arching their backs like cats and screeching at disasters when none are there. After so many years of enforced political quiet in the Soviet Union, Muscovites often show the same reflexes as the party's old guard, mistaking the confused music of political pluralism for the rumble of conspiracy and civil war.

But to be in the Soviet Union these past months is to live in an uneasy state. On Red Square this May Day, who could watch the demonstrators with their defiant placards and even a Soviet flag with its hammer and sickle ripped out and not think with a shiver of Bucharest in December? Who could watch the tanks parade by the parliament building in Vilnius and not anticipate the worst? Who can read the articles in Nash Sovremenik calling for an alliance of the army and the "Great Russian People" and not feel uneasy? It becomes clearer every day that when Andrei Sakharov died last December, the country had lost its moral and political sense of balance just at the moment it needed it most.

When Gorbachev made his first visit to Washington two and half years ago, his political life was, at least by his standards, simpler. He was in the midst of a euphoric transformation of Soviet culture and politics. Even the most difficult times were balanced with liberating surprises: the publication of Orwell's "1984" and Anna Akhmatova's "Requiem"; the rehabilitation of Bukharin and the millions of other victims of Stalin; the formulation of "new thinking" in foreign policy; and, later, the creation of a parliamentary system. The simple tableau of Sakharov ambling slowly up the steps to the speaker's podium on the opening day of the Congress of People's Deputies last year was an astonishment, a promise.

The most effective moves were the ones Gorbachev could initiate almost single-handedly, by diktat. Pressed by circumstance and fired by a leap of political imagination and daring, he re-shaped Soviet behavior abroad, took history and culture out of the hands of the police and initiated the politicization of a people who for 70 years had conceded their own powerlessness in the face of tyranny.

From the start, Gorbachev has been a fascinating Soviet politician because he is able to evolve, to jettison the orthodoxies of his own history. The central fact of his biography is that he was able to succeed within the Communist Party hierarchy, an anti-culture of sycophants and secrecy, while at the same time preserving a measure of intellectual independence. He could please party masters as tainted as Andropov, Suslov and Gromyko and still survive with enough self-possession to learn, to do all that he has done so far.

But where once Gorbachev appeared the unchallenged colossus of his era, its architect and master, he now spends much of his time reacting, containing, negating. His need to reassure the beleaguered military and Communist Party faithful now holds him back from joining an advancing parade of younger reformers. Gorbachev seemed just as ill at ease during the huge military parade in Moscow May 9 as he did at a similar event in East Berlin last year in the final days of Erich Honecker. But clearly Gorbachev cannot do to his own defense ministers what he did to Honecker that day: kiss him goodbye.

In Washington, Minnesota and California this week, Gorbachev will undoubtedly try to match the euphoria of December 1987. Although the novelty of these expeditions has worn off considerably, Gorbachev is still a terrific performance. But mainly on the road.

In Moscow, the strain is evident. He looks older, heavier, even bewildered by the knowledge that much of the country turns to him not with gratitude, but rather with impatience and anger. He has discovered that his people consider liberty an intrinsic right rather than a gift granted from above. They want more: a normal economic, as well as cultural, life.

"At first, we believed in the ability to reform the country completely from above, but all that has changed," says Ilya Zaslavski, the young, disabled politician who has turned the Oktober region of Moscow into the Berkeley and Greenwich Village of Soviet politics.

"When we began to see Gorbachev hitting his limits, a lot of us decided the only way to force real change was on the grass-roots level -- revolution from below. We couldn't stand around waiting for one man to evolve as fast as we were."

The new generation of politicians, unburdened by a lifetime in the Communist Party, talk freely of private property, a bill of rights, Baltic secession. To understand Soviet public life now, it is no longer enough to know the faces of the Politburo: In fact, there are kid-politicians in their thirties who are now at least as important to the country's future as some members of the Politburo.

Ilya Zaslavski is one. Since becoming chairman of the Oktober region this spring, Zaslavski has allowed one new party after another to use the auditorium of the local Communist Party committee to hold their founding conferences. "It's an open stage," he says. "If they can't get a room at the Kremlin, they can start their parties here." Zaslavski has also helped sponsor the official publication of such underground papers as Sergei Grigoryants' Glasnost and Alexander Podrabinek's Express-Khronika.

Gorbachev has little problem with former socialist dissidents like the historian Roy Medvedev who have become unfailing loyalists. But he does not go to any effort to conceal his suspicion for radicals like Gavril Popov. At a recent session of the legislature, Popov devastated the government's plans for a slow conversion to a market system, attacking it as too little, too late. Asked in the foyer about Popov's speech, Gorbachev darkened a bit and said, "Academics get in trouble when they try to get involved" in policy. Well, now Popov is no longer merely the editor of "Questions of Economics." He is mayor of Moscow and he has a plan for revolution in one city.

Popov and his young deputy, political scientist Sergei Stankevich, are now revolutionizing the new Moscow City Council, introducing plans to seize properties from the Communist Party and return them to the city and to create thousands of private farm plots around the city to help ease the food shortages. Gorbachev must have gotten an awful sense of the future on May Day when he stood on the Lenin Mausoleum next to Popov and realized that all those tens of thousands were Popov's people more than his own.

This rise of a new political generation goes beyond the capital. In Leningrad, a lawyer named Anatoli Sobchak has just been elected mayor in the midst of a pitched battle against the city's conservative Communist Party apparatus. Two women in the Baltics have been especially impressive: Kazimera Prunskiene, an ex-communist who has become a free-market advocate and the most effective politician in Lithuania, and Marju Laurstin, the daughter of a prominent Estonian communist and now the most dynamic voice for republican independence and social democracy.

In the coal-mining city of Karaganda in Kazakhstan, a 28-year-old miner named Pyotr Schlegel is the head of a local miner's union and strike committee and is the most powerful figure in town. If you need help, people in Karaganda say, you go to Pyotr, not to the party.

The new mayor of Lvov, the former political prisoner Vyacheslav Chernovil, has donned a suit to help make the Ukraine, a republic of 50 million, independent of Kremlin control.

Little more than a year ago when I visited Lvov, I wanted to meet with Chernovil. To do that I had to meet first with other members of the Ukrainian Helsinki Union in a city park -- the better to avoid any unwanted visitors. When I finally met with Chernovil at his apartment, he said, "Gorbachev is a great advance but he is not the end of the story. He is carrying on a great transition, but it is just that -- a transition. He is not in a position of carrying things out to the end."

All this is not to suggest that Gorbachev will soon be packing for retirement. The Sovietologists who make a living betting on the length of Gorbachev's tenure as if it were a daily-double are playing the wrong game, answering the wrong question. There is hardly a single person in the range of political opinion, from the whey-faced anarcho-syndicalist to the lumpen leaders of the Workers' Front who believes there is in the immediate future an alternative to Mikhail Gorbachev. The latest version of the overthrow rumor -- with the army leading a Bonapartist revolt -- seems farfetched.

The rise of the multi-party system really only began a few months ago. Social Democrats, Constitutional Democrats, Greens and all the rest are still at the stage of gathering in groups of a few hundred to pore over blurry mimeographed programs and carry on Talmudic debates that sound like the first sessions of the pre-revolutionary Duma. In the meantime the only politician with a national constituency large enough to make Gorbachev truly queasy is Boris Yeltsin, a born-again radical, but a Communist Party apparatchik to the core. Yeltsin's daring campaign to become president of Russia, the U.S.S.R.'s dominant republic, suggests again how he is bound to make life harder for Gorbachev.

But the disenchantment is not limited merely to politicians. The liberal intelligentsia of Moscow, a vast community of scientists, artists, scholars and professionals, once idolized Gorbachev as a kind of savior, a miracle within the Communist Party. There was a time when Gorbachev could win that community's affection with a gesture, a silence.

Just after he was made Soviet leader in March 1985, Gorbachev met with a group of writers, old guard and new. "In those days Mikhail Sergeyevich did more listening than talking and he asked us, 'So, comrades, what do you want?' An astonishing question," says Mikhail Shatrov, a playwright and liberal of Gorbachev's generation.

One of the bigshots in the Writer's Union, began talking about the need for repairs to the union building: re-plastering and the rest. Gorbachev nodded. Then the editor of the monthly journal Moladaya Gvardia, a frightening neo-Stalinist named Anatoli Ivanov, thought he understood Gorbachev's invitation a bit better. He rose and said the party ought to begin a purge of all heretics much like what was accomplished in 1946 when great writers such as Akhmatova and Zoschenko were persecuted by decree.

"And the most amazing thing happened. Gorbachev was just quiet, and you knew he and Ivanov were not thinking alike," says Shatrov. "It was a liberating silence for us, one we had waited decades for, and soon we all rose to attack Ivanov and defend the need of artists to work freely."

But now at these meetings, Gorbachev does more talking than listening, and he is just as likely to attack a progressive editor as a reactionary. The other day, Shatrov helped start a Gorbachev Fan Club. So far, membership is extremely low.

David Remnick is a Moscow correspondent for The Washington Post.