MOSCOW Russian Prime Minister Vladimir Putin is in little immediate danger of being toppled by a wave of opposition protests but they could mark the beginning of the end for him if he does not make changes to restore his legitimacy.
As riot police rounded up hundreds of protesters chanting "Russia without Putin!" in central Moscow earlier this week, Putin was visiting an exhibition of paintings by Italian artist Michelangelo Caravaggio in another part of the city.
The message he wanted to send was clear: it's business as usual for Russia's paramount leader. He can ride out protests in Moscow and St Petersburg and has nothing to fear from a planned day of protests nationwide on Saturday.
But visiting an art gallery while protesters were being carted away in police vans could also convey the impression that the man who has ruled Russia for more than a decade is out of touch with the people -- a potentially fatal political error.
Conventional wisdom is that Putin can ride out these protests and return to the presidency in an election in March, but his authority will keep falling if he fails to respond to the growing signs of discontent.
"He can crush the protests, he can crush the rally on December 10 and he can crush future rallies but that cannot save him in the historical perspective: the recent events have delegitimised his power," said political analyst and author Liliya Shevtsova.
Shevtsova said that although the protests were sparked by allegations of vote-rigging in Sunday's parliamentary election to favour Putin's ruling United Russia party, he was the real target of the rallies.
"We are witnessing the decline of Putin's epoch," she said.
"The death throes could end this year, next year, maybe in two years time but it has ended and the leader who has lost legitimacy, who has St Petersburg and Moscow against him, cannot rule Russia. The clock is ticking."
Much will depend on the tactics the 59-year-old leader deploys in the coming days and weeks to deal with the problems, and whether the protests spread for any length of time beyond Russia's two biggest cities.
That test will come on Saturday, when protests are planned across the country, from Kaliningrad on its western top to Vladivostok in the far east, including cities in Siberia, the Ural Mountains, Russia's Arctic North and its southern rim.
But coordinating protests across a country covering 17 million square km (6.6 million square miles) is not easy, especially in winter.
"It won't be long before the protests fade. Anger over the election may keep them going for a while but there's no idea of what to do next. The leaders are competing with each other," said Lev Gudkov, head of the Levada Centre polling organisation.
"To keep going, you need some kind of a political platform and a plan of action. I just don't see that."
Putin's strengths are his political experience after 12 years in power, his tight grip on traditional media, and the state apparatus he has at his disposal, including the armed forces, police and the ability to open the state's purse to appease some of the protesters.
Russia has little tradition of major street protests and many Russians still show faith in the state as their main provider, a trait strengthened in Soviet times. The 1917 Bolshevik revolution itself was more a putsch by a well-organised group than a mass uprising.
Gudkov said the chances of the protests becoming a nationwide revolt were limited because many of the protesters are middle-class voters and youth in big cities whose interests do not necessarily coincide with those of the more than 140 million population as a whole.
"The youth in the provinces tend to back Putin. More than other groups, they see him as a symbol of success, a macho and natural leader," Gudkov said. "It's a different mood to Moscow where discontent built up in the two weeks before the election and could disappear just as quickly again."
Such observations reinforce the view of many that Putin will be able to survive the immediate threat.
"I think he's got a kind of warning, has been told by the population: 'We don't like what's going on'," said veteran political commentator Vladimir Pozner.
"I think that when presidential elections come around he's going to win. Who else can you possibly vote for?"
But the end of the protests would not be the end of the story for the former KGB spy who won respect among Russians by restoring order after the chaos that followed the collapse of the Soviet Union and reined in Russia's unruly regions.
The protests have served notice that opposition is growing and discontent is mounting over corruption, a tightly controlled political system dominated by one man and the huge gulf between rich and poor. These are the areas where protesters want change.
It is not just Putin who is under threat. The whole political system, dominated by one person, that he has built around himself since his 2000-2008 presidency is at risk.
As prime minister since 2008 he has remained the dominant force under an arrangement with his protege, President Dmitry Medvedev.
The business newspaper Vedomosti said he had built "cardboard scenery around himself" and prevented any real political processes.
Many Russians were outraged in September when Putin and Medvedev announced plans to swap jobs after the presidential election in March, showing the pupil had just been keeping the seat warm for the teacher for four years to skirt a constitutional ban on three successive terms as president.
"If nothing changes, the whole (political) structure could collapse. This system will not last five years more," Mikhail Prokhorov, a metals tycoon who fell out with the Kremlin after a brief political career, wrote in his blog.
Putin's critics grimace at the thought that if he wins two more presidential terms, he could rule until 2024, and make unfavourable comparisons with Soviet leader Leonid Brezhnev's 18-year rule, widely seen as an era of stagnation.
Shevtsova, and a source close to the Kremlin, said the prime minister had three possible courses of action.
"The situation is grave but manageable, and there are several ways to resolve it: radical change, which is unlikely as it could destabilise the situation, populism or tough measures. I think populism sprinkled with some minor changes to the system is the most likely variant," the source said.
"The tough option - cracking down - could lead to a catastrophe in Russia but the leaders do not want this."
The Russian leadership has already had some success in dousing the protests in Moscow by mounting a show of force, rounding up many of the protesters -- some before they even reached the protest rallies -- and sending pro-Kremlin youth to the opposition protests to drown out their anti-Putin chants.
Courts have also sentenced two prominent opposition figures -- Ilya Yashin and Alexei Navalny -- to 15 days in jail for their roles in the protests.
Putin on Thursday accused the United States of encouraging the protests and said foreign countries were pouring money into Russia to influence elections.
He is also expected to distance himself from United Russia, which won only a slim majority in the State Duma lower house of parliament in Sunday's election. His ratings are much higher than those of his discredited party.
TENSIONS RUNNING HIGH
There is no suggestion that opposition leaders will face harsher punishment than short jail terms even though one of Putin's critics, former oil tycoon Mikhail Khodorkovsky, received a 13-year jail term on charges of financial crimes after falling out with him. But feelings are running high.
"Look at what they have done to our country, our Russia," said one protester, who gave his name only as Alexei, as he was detained by police.
Another protester, Mikhail Torupov, said he was protesting "because I can't stay quiet about how they just spit on us."
Putin is likely to struggle to appease the protesters if he continues to act in public as though nothing has changed.
"It is my hope that Putin understands that this was not purely a vote against United Russia, but a vote against him getting back (to the presidency)," said Vladimir Frolov, president of LEFF Group, a government-relations and PR company.
Some analysts say that if Putin's response to the situation disappoints voters, he might lose some of his support in the presidential election to the resurgent left-leaning Just Russia party -- a vote for whom would be a safe protest vote.
"In most configurations, Putin will get more than 50 percent of votes and win in the first round. If Just Russia choose a strong candidate, it could mean a second round," said political analyst Andrei Piontkovsky, suggesting a woman economist, Oksana Dmitrieva, 53, would be the party's strongest candidate.
(Additional reporting by Guy Faulconbridge, Douglas Busvine and Polina Devitt)