EVEN fans of the Five Star Movement, an Italian political group often described as populist, maverick and anti-establishment, would never have credited it with slickness. So when the campaign video for Virginia Raggi, a 37-year-old running for mayor of Rome as the Five Star candidate, appeared online in late February, it came as a shock. Mute the soundtrack on Ms Raggi’s video, in which she declares that “we can again be a world city”, and her sharp suit and on-message presentation might be those of an aspiring Democratic congresswoman in America or Tory politician in Britain. A talented debater, Ms Raggi illustrates how Italy’s second-biggest political group is increasingly coming to resemble a normal party.

Polls are continuing to give the Five Star Movement a quarter of the electorate: about eight percentage points behind the governing centre-left Democratic Party (PD), but ten percentage points ahead of the right-wing Northern League. In Rome, a city that has long suffered from neglect and corruption at the hands of mainstream parties, Ms Raggi stands a fair chance of success when the vote is held, most likely in June. That she should have a video ready before her rivals hints at both the importance the Five Star Movement attaches to her campaign, and to its growing professionalism.

The enduring popularity of the group is all the more remarkable in view of recent setbacks and upheavals. In different ways, it is the most and least democratic of Italian political movements. Disdainful of conventional democracy, its leaders believe the internet offers a chance to return to an Athenian-style, direct democracy in which every major political issue would be submitted to an online referendum. Within the movement, online ballots are used to set policy and select candidates (and also to expel elected representatives who fail to abide by its strict rules).

But the really big decisions, over whether or not Italy should stay in the eurozone and the like, have always been taken by its two unelected co-founders: Beppe Grillo, a satirical comedian, and Gianroberto Casaleggio, a political activist and entrepreneur.

Although since last year Mr Grillo has started to concentrate more on his stage career, his influence is still decisive. Last month, as the Senate debated a bill to legalise civil unions, including same-sex partnerships, Mr Grillo unexpectedly announced he would give Five Star Movement senators a free vote on a clause that would allow gay partners to adopt each other’s biological offspring. Many Catholics and conservatives feared the provision would encourage surrogate births. The Movement subsequently withdrew its support for a motion that would have allowed the clause to go through unchallenged. That wrong-footed the PD, which had assumed the movement would not antagonise gay people. The PD had to turn to the centre-right for support. The measure went through without its contentious clause.

Commentators accused Mr Grillo of cynically pitching for right-wing votes in preparation for the election in Rome. But Mr Casaleggio said the decision was partly due to “different sensibilities” in the Movement. It is far less radical than Greece’s Syriza government or Spain’s Podemos. United by a loathing for Italy’s tainted mainstream parties, Five Star activists are a heterogeneous bunch, often disagreeing on issues such as privatisation or abortion. Most are progressive, some distinctly conservative. Mr Grillo is critical of the euro and happy to hobnob with Nigel Farage, leader of the UK Independence Party, which is trying to get Britain out of the EU. If it is to become a mainstream party of government, such differences will need to be settled.