On Thursday, Russian dissident-blogger-turned-opposition-leader Alexei Navalny was sentenced to five years in jail on old minor embezzlement charges that had previously been thrown out as baseless. The conviction means, among other things, that Navalny probably won't be able to compete in Moscow's mayoral race in September; he became an official candidate on Wednesday.

Navalny, a 36-year-old lawyer and anti-corruption crusader widely considered the most charismatic of Vladimir Putin's opponents, is most famous for coining the nickname "party of swindlers and thieves" for Putin's dominant United Russia party. The name stuck, and is credited as a factor in the party's humiliating, allegedly fixed, narrow win at the polls in December 2011. After that election and in 2012, Navalny brought tens of thousands of people out to protest, the biggest anti-government demonstrations of the Putin years.

The demonstrations, plus Navalny's success in uncovering various forms of corruption and undisclosed wealth among high-ranking United Russia officials, have made him a big headache for the Kremlin, and allegedly a big target. The belief that the embezzlement trial was a retaliatory gesture is so widespread that the judge who convicted him felt moved to say in his verdict: "Assertions to the effect that Navalny is prosecuted for political motives are far-fetched."

Few people seem to agree. The verdict was based on the testimony of another suspect in the alleged scheme, Vyacheslav Opalev, who pleaded guilty and turned state's witness. "In his decision, Judge Sergei Blinov called his testimony trustworthy and reliable," says David M. Herszenhorn in The New York Times. "But during the trial, Mr. Opalev at times gave contradictory evidence, and defense lawyers were not allowed to cross-examine him." The judge also blocked 13 defense witnesses from testifying. Judge Blinov hasn't acquitted a defendant in his past 130 cases.

Even the Kremlin seems pretty open about the political nature of the case. After the verdict, Vladimir Markin, spokesman for the federal Investigative Committee — Russia's version of the FBI — blamed Navalny for his own legal woes: "If a person tries with all his strength to attract attention, or if I can put it, teases authorities — 'look at me, I'm so good compared to everyone else' — well, then interest in his past grows and the process of exposing him naturally speeds up."

Navalny's supporters were still surprised by the severity of the verdict, and the fact that Judge Blinov ordered Navalny to serve the time in jail — many observers had predicted a suspended sentence. But they drew some comfort from the fact that he was found guilty on Nelson Mandela's 95th birthday, and the belief that the Russian government was making the same mistake with Navalny that South Africa's Apartheid government made by jailing Mandela.

"It is quite symbolic that Navalny is sent to prison on Nelson Mandela's birthday... indicating that the Kremlin is doing its best to grow a Russian Mandela," Andrei Piontkovsky at the System Analysis Institute tells the Los Angeles Times. "Navalny is backed by a group of powerful oligarchs and his imprisonment can create a serious split in the ruling elite with a strong possibility of anti-Putin conspiracy at the very top." Putin, he adds, "is committing a very serious if not lethal mistake indulging in an act of personal vengeance."

The New York Times' Ellen Barry similarly thinks Putin has crossed into uncharted territory:

"Fabricated charges against the Kremlin's political opponents are nothing new in Russia," says Brian Whitmore at Radio Free Europe. But in this trial, which bounced back and forth from the absurd to the "truly Orwellian," Russian authorities "seem to be pushing the envelope of believability into new territory." And unlike past shows of political strength and intimidation, says Whitmore, this case "reeks of desperation."

Kremlin allies don't see it that way. In their telling, Navalny is a stooge of the West, paid by powerful anti-Putin interests to stir up trouble. "There will be no political consequences and repercussions in regard to the verdict," Sergei Markov at the Russian Plekhanov Economic University tells the Los Angeles Times. Navalny is nothing more than "a would-be leader of an anti-Putin revolution, a plan which is now doomed to failure."

Actually, jailing Navalny is "one of the most significant verdicts since Vladimir Putin came to power," says Daniel Sandford at BBC News. And Putin could rue making a martyr of his opponent — or he could know what he's doing.

"The whole Navalny case is viewed by the Kremlin as a warning to society," Lilia Shevtsova, an analyst at the Carnegie Center in Moscow, tells the BBC:

Vladimir Putin would like society to accept the new rules of the game, and the new rules are "You have to obey us on the principle of total and absolute loyalty. You don't have the right to have ambitions, you have no right to fight for power. Loyalty is the main principle of your behavior." [BBC News]

Lots of young Russians, who followed Navalny on social media and supported his anti-corruption drive, will be furious over the ruling, Shevtsova says. In that sense, "Navalny is becoming a martyr, a new Russian Mandela." But their numbers aren't large enough, so "there is no danger for the time being of a massive tide. Overall the mood within the population at large is pretty quiet." Russians are fed up with Putin, but at this stage, they don't see Navalny and his nascent movement as a viable alternative.

In the meantime, now more than ever, Vladimir Putin's Russia appears to be a free country only in the Janis Joplin/Kris Kristofferson meaning of the word: