The Internet helped power the massive protests that unsettled the Kremlin this winter, but as the tech-savvy opposition movement struggles to expand beyond Russia’s biggest cities, leaders are finding that old-fashioned shoe leather is still the best way to spread their message.

The lurching realization came this month in the provincial city of Astrakhan, where an opposition mayoral candidate who said an election had been stolen from him went on a hunger strike. Few in the city realized what was happening until protesters stepped back from their blogs and Twitter accounts and resorted to methods from an earlier era, using a labor strike and disruptive theatrics to win quick concessions and publicize their grievances.

Now, back home on the Web, protesters are talking about how to build on-the-ground organizations across the country that cast the Internet in a supporting role only. Finding a way to do it will be critical if they are to broaden their appeal beyond Moscow and St. Petersburg, which together hold just 11 percent of Russia’s 143 million residents, who are spread over nine time zones.

If the protesters succeed, they will have struck a major blow against the dominance of Prime Minister Vladimir Putin and his associates, they say. If they protesters fail, they will continue to have difficulty reaching the four in five people whose main source of news is television — from which the protesters remain largely excluded. Putin, who is about to begin a six-year term as president, may have an opportunity to beat back their momentum.

“The tactics are simple,” said Ilya Yashin, an opposition organizer who once wrote a step-by-step guide to organizing street protests. “When you have no opportunity to go on TV, you go and you shake a million hands.”

‘A kind machine’

After the fall of the Soviet Union, an irreverent independent media quickly emerged from the rubble to challenge Russia’s powerful elites. But when Putin came to power in 1999, he swiftly put the country’s major television networks back under Kremlin control.

The vast majority of Russians get their news from the three main channels — which this month meant that the residents of Astrakhan saw nothing about the opposition hunger strike until it had been going on for four weeks. And 46 percent of Russians say they don’t use the Internet at all, according to a March poll by the independent Levada Center, foreclosing any possibility that they might catch a whiff of the discontent rife in online forums.

Moscow protest leaders have been talking about the need for better communication as they search for ways to reach people in the provinces.

“We just need to organize everything and decrease the confusion and miscoordination by 30 percent. And then we will win,” Alexei Navalny, an anti-corruption blogger and protest leader, wrote on his blog this past week. He called on supporters to build a “kind machine of propaganda,” in contrast to what he described as the Kremlin’s “evil machine of propaganda.”

‘The bubble can burst’

The opposition’s best opportunities, leaders say, are a series of mayoral elections, each one of which Navalny has said he hopes will turn into a “political crisis.” But elections in the Siberian cities of Omsk and Krasnoyarsk will be held in June, leaving relatively little time to prepare. A third election, in central Russian Nizhny Tagil, is scheduled for October.

Those races are not about to eject Putin’s United Russia party from power nationally, but they could be enough to keep the Kremlin off-balance and give the opposition a toehold on local control that could help it launch larger efforts.

Since last month, opposition candidates have won mayors’ offices in two cities — both after campaigning under tough conditions with no access to local media. And in Astrakhan, a city of 500,000 near the Caspian Sea, authorities were concerned enough about post-election protests that they flooded the city center with hundreds of riot police.

“Astrakhan has been successful in proving that the bubble can burst at any moment in any place,” said Lilia Shevtsova, a political analyst and Putin critic at the Carnegie Moscow Center. “There’s such ferment going on.”

The protesters there this month used tactics more reminiscent of the American civil rights movement of the 1960s than of wired 2012. The mayoral candidate, Oleg Shein, walked a group of two dozen journalists and supporters into a closed-door committee meeting at the regional parliament, surprising the journalists and the local politicians sitting around the table. The politicians quickly agreed to Shein’s demands that they take up his grievances before the full legislature.

Shein, a veteran labor organizer and local politician, said the ploy was “absolutely spontaneous.”

“If it hadn’t been for journalists, I don’t think it would have been possible” to win the concessions, Shein said. “When we have publicity, we can talk about developing democratic tools.”

Days after Shein crashed the committee meeting, many of the city’s bus drivers were roped into the cause. They had been poised to go on strike because their contracts were expiring. Fifty of them took a day off, surrounding the old fortress at the city’s center with their vehicles and making it difficult for anyone to ignore the ongoing tumult.

The protests seem unlikely to win the desired new elections, because Russia’s Central Election Commission has said it does not believe that violations were enough to swing the results of the vote. And organizers have struggled all along to surmount apathy and get people into the streets.

Still, they say they have again expanded the range of possibilities for the open expression of discontent.

“We will put an ad on the wall, or we will distribute this information via people we know, from one to another,” said Denis Gavrilov, an events organizer in Astrakhan who is one of Shein’s supporters. “We need the activists, and it’s not hard to inform them, even if they don’t have the Internet. First them, and they will start working with other, less active, citizens. It will be like a chain reaction.”