Few of the Russians who intend to turn out Saturday to take part in what could be the largest push for democracy here in decades expect an early Christmas present.

They do not voice confidence that their demands — an end to corruption, a more open political life — will be met overnight. And it is not yet clear what direction the new activists will take in the future.

Their protests have already drawn promises of reforms unimaginable a month ago. President Dmitry Medvedev announced Thursday that the Kremlin would take steps to liberalize politics, reduce corruption and free the media. On Friday, he introduced legislation to start the process.

Many protesters dismiss that response as window dressing and insist that they will not stop demonstrating after Saturday, or after a March election in which Russians will almost certainly elect Prime Minister Vladimir Putin as president for a six-year term. According to activists and observers, the young, post-Soviet generation that struck a 12-year-long bargain with Putin — a dormant political life in exchange for personal freedom — has abandoned that deal for good.

Yet the movement’s path remains vague, and one of its strengths — support from a wide swath of Russian society, from fed-up liberals to angry ethnic nationalists — is also a weakness, as leaders struggle to work together and supporters appear united more by what they dislike than by what they seek.

Many of the mostly young, mostly middle-class protesters are taking to the streets for the first time, too young to have played an active role in the Soviet Union’s downfall 20 years ago Sunday. Few are committed to a single leader, and so far, the Internet-savvy activists with whom they most identify have spurned electoral politics.

“People are coming to the streets, and they don’t have any particular program. They’re looking for one,” said Alan Gasanov, 45, an information technology sales manager who was a spectator this week at a planning meeting for the protest. “I do not think this situation is going to resolve quickly.”

The unhappiness was set off in September when Medvedev and Putin announced that they would swap jobs, returning Putin to the presidency after he was forced by term limits to take a break in 2008. The announcement had the effect of rendering the March presidential election a mere technicality, which was a step too far for the generation that has prospered during Putin’s years in power. Then Dec. 4 parliamentary elections that garnered allegations of widespread fraud pushed the situation to the brink.

In Moscow on Saturday, protesters will gather on Sakharov Prospekt, a wide boulevard named after the famed dissident whose writing helped speed the Soviet Union’s end. They will listen to today’s dissident leaders — blogger Alexei Navalnyand activist Yevgenia Chirikovaamong them — and also a figure from the past: Mikhail Gorbachev, 80, the final leader of the Soviet Union.

Gorbachev may serve as a potent reminder to Putin, an ex-KGB colonel who is known as an astute student of Soviet history, of how to handle demands for change — and how not to. Though Gorbachev remains more highly regarded outside Russia than at home, the protesters may see his presence as symbolizing the value of loosening the reins of power.

“Russia is entering perestroika number two right now,” said Stanislav Belkovsky, a political analyst, referring to Gorbachev’s reform program. “The active minority is refusing to support Putin.”

On Friday, nervous Russians chattered among themselves: Would the pro-Kremlin youth movement come out? Would there be arrests? How many people would show up? Some predicted that the protest would fizzle if it did not surpass a Dec. 10 protest in which tens of thousands took to Moscow’s streets.

The organizers have a permit for 50,000 people. As of late Friday, more than 49,000 had said on Facebook they would come out for one of the last chances to protest before the country goes on a long holiday between New Year’s Eve and Orthodox Christmas, celebrated Jan. 7. Organizers are hoping for far more, a development that could make Saturday’s protest the largest since the fall of the Soviet Union but could also set up a confrontation with police.

Even Russia’s modern-day Communist Party, which has previously distanced itself from the protest movement, plans to come out Saturday, at least in Moscow, where a local leader, Yevgeny Dorovin, complained that Putin “had more power than Stalin and Mao together.”

Still, for now, the movement remains an urban one. As if to underline that fact, the independent Levada polling firm released a poll this week in which the number of respondents who said they would vote for Putin if the elections were held on Sunday had increased by 5 percentage points in the past month, to 36 percent. No one else tops 7 percent.