Virginia Raggi’s triumph in Rome made her the first female leader of the capital since it was founded over two and a half millennia ago.
And it was a win based on exactly the kind of pro-change platform and mood that had, until now, underpinned Renzi’s popularity.
READ MORE: Rome set to elect first female mayor
In his first reaction to Sunday’s losses, Renzi made light of the setbacks, stressing big regional variations and arguing that the gains for M5S reflected a desire for change that his government shared.
“Those who won yesterday were those who knew best how to reflect this longing for change,” he said.
The ruling council of his Democratic Party (PD) will hold an inquest into the result of the vote on Friday.
Analysts saw the outcome as worrying for the premier because the landmark victories were achieved by M5S securing the backing or the abstention of anti-Renzi forces encompassing the far-left, the far-right and the centre right.
The redrawing of Italy’s political landscape came four months before a crucial referendum on constitutional reform. Renzi has vowed to quit if he loses the vote on streamlining Italy’s parliamentary and electoral systems.
“The government will help all (the newly elected mayors) to try and do good. And we will move forward to take care of our institutional priorities,” he said Monday.
Economist Lorenzo Codogno commented: “The bottom line is that the PD is losing ground in favour of anti-establishment parties.”
Codogno said the vote also marked the emergence of a “more hands-on and pragmatic” breed of M5S politician which could make the party more electable in 2018.
Roberto D’Alimonte, director of political science at Rome’s LUISS university, said Renzi should be concerned by the results.
“It makes the referendum in October more complicated,” he said. “If the constitutional reform is not approved there will be a ‘Rexit’ (Renzi’s departure) and chaos will ensue. Instability in a country with debt at 130 percent of GDP will pose a very big problem for Europe.”
Both the new M5S female mayors are successful career women from well-heeled backgrounds. They ran campaigns which largely avoided national issues such as the party’s support for a referendum on leaving the eurozone.
And their sober tone contrasts markedly with the ranting of M5S’s acerbic figurehead and founder, comedian Beppe Grillo.
The victory in Rome surpassed all expectations with Raggi, 37, taking 67 percent of the votes cast in a run-off against the PD’s Roberto Giachetti.
In Turin, where the anti-immigrant, anti-EU Northern League is an influential player in local politics, Chiara Appendino, 31, claimed just over 54 percent to oust long-serving PD heavyweight Piero Fassino.
The only consolation for Renzi was that the centre-left held on to Milan, where the former World Expo director Giuseppe Sala squeezed home in a more traditional fight with a centre-right rival. Centre-left candidates also claimed anticipated wins in Bologna and Naples.
“For the first time Rome has a female mayor in an age where equality of opportunity remains a mirage,” Raggi said in a victory speech.
The career lawyer, a mother of one who is separated from her husband, promised to restore legality and transparency to the city’s institutions.
Appendino, a multilingual businesswoman who helps run her family’s laser equipment company, struck a similar note.
“We have made history,” she said. “This was not a protest vote, it was about pride and change.”
Raggi was virtually unknown a few months ago and has no experience of running anything.
But she ran a shrewd campaign that tapped into deep reserves of anger among voters over the dilapidated state of the capital’s streets, public transport and garbage management.
Her cause was helped by the ousting of her predecessor, the PD’s Ignazio Marino, over an expenses issue and a much bigger scandal over organised crime’s infiltration of the city administration.
Raggi has vowed to make such abuses impossible and get public services back on track.
But LUISS expert D’Alimonte described the challenge facing her as “mission impossible.”
“Rome is a complicated city and she will have the major handicap of not being supported by the government of the country.”