ALEXEI NAVALNY’S election headquarters looks like a set for a film about American presidential elections. The small Moscow building is bustling with young volunteers brainstorming, tapping away on their MacBooks, carrying boxes of advertising materials, signing up artists. Tagged the “Navalny Team”, they are energised with coffee and Mr Navalny’s slogan: “Change Russia—start with Moscow”.

Mr Navalny, the leading opposition candidate in the Moscow mayoral election on September 8th, has campaigned relentlessly over the past months, raising money, holding three rallies a day, meeting voters in every district, giving dozens of interviews. He broke a television blockade by reverting to street politics. His election advertising has reached nearly 70% of Muscovites and his popularity rating has risen from 3% to about 20%. And although Sergei Sobyanin, the Kremlin-backed incumbent who enjoys blanket television coverage, has a rating above 50%, which could enable him to win in the first round, this outburst of political activism in Moscow is as important as the result.

Mr Navalny says many of his ideas, including makeshift street podiums with chairs for the elderly and umbrellas in case of rain, have been copied from “The Wire”, an American television drama. A charismatic 37-year-old lawyer in jeans and a white shirt with rolled-up sleeves, Mr Navalny acts like an American politician. In a country where politics takes place behind the high Kremlin walls, this is new.

Mr Navalny also appeals to private business. At a recent dinner with investment bankers at the Ritz Carlton, a swanky hotel in Moscow, many, including those working for state-owned banks, openly pledged their support. Earlier, several dozen internet businesses signed a “social contract” with Mr Navalny.

The contrast with a few months ago is striking. Back then Mr Navalny was handcuffed and sentenced to five years in jail on apparently fabricated charges and civil-society groups were under assault. The threat of a crackdown has not gone away, but its execution has been temporarily suspended. This reprieve came as suddenly as the release of Mr Navalny from custody pending an appeal, aimed at making the election more legitimate. There is even talk of counting the votes fairly and transparently—something that Moscow has not seen for years.

One explanation is that Mr Putin decided to stage a carefully controlled experiment, testing the mood in the capital two years after the announcement of his job swap with Dmitry Medvedev, then the president and now prime minister, prompted mass protests.

The Kremlin has always seemed split over how best to deal with protests. The crackdown favoured by the siloviki, the men of force, has not yielded the desired results. People have continued to come out on the streets, in smaller numbers, but with greater resolve.

Mr Sobyanin has favoured a more subtle approach. Although hardly a liberal, he sought to placate and co-opt the respect-seeking middle class by creating perks and promoting the illusion that Moscow is a typical European city. Ranks of shiny red city bicycles sprang up, parking meters were put in place, city parks and playgrounds revamped. Andrei Sharonov, Mr Sobyanin’s outgoing deputy in charge of the economy, says the aim was to create a more comfortable urban space and cut red tape for business.

A fair mayoral election, with Mr Navalny as an opposition candidate, was supposed to complete the picture of Moscow as a special zone. But as Mikhail Iampolski, a cultural historian, argued in a recent article, whereas two years ago the protest was about rules and elections, it has now become more overtly political. In Mr Navalny’s eyes the regime lacks legitimacy because it is corrupt and morally bankrupt, not because of the way it counts votes.

Yet, as Mr Navalny’s ratings show, the number of Muscovites who are prepared for radical political action is limited. Some are put off by Mr Navalny’s populism and nationalism. Others are content with the improvements made by Mr Sobyanin.

Mr Navalny knows he will not win this election, but his goal is to create a base and turn thousands of volunteers into a political force. The Kremlin may decide to abort its experiment and put Mr Navalny back in jail, or it could give him a suspended sentence, barring him from future elections. Whatever it does, it cannot kill the demand for political change, which has produced Mr Navalny.