Beppe Grillo, leader of the Five Star Movement, delivers a speech in Piazza San Carlo in Turin, Italy. (AFP/ Getty Images)

When Beppe Grillo started to make headlines as the leader of Italy's biggest protest party more than six years ago, it was hard to avoid the puns. A comedian turned politician, Grillo was laughed at and branded a “clown.”

But by 2013, the laughing subsided, and German magazine Der Spiegel already had called him “the most dangerous man in Europe.” Three years later, he may finally be living up to that description, his critics say.

On Sunday, a majority of Italians voted against legislative revisions in a referendum, according to major exit polls. Italian Prime Minister Matteo Renzi, who had pushed for the changes and was forced to call the referendum, admitted defeat Sunday evening and announced that he would hand in his resignation Monday. 

Italy's Prime Minister Matteo Renzi announced his resignation on Dec. 4, after losing a referendum on constitutional reform. Campaigners who opposed his plans, including the anti-euro Five Star Movement, celebrated the announcement. (Reuters)

Earlier this year, Renzi failed to secure the needed two-thirds parliamentary majority for a controversial bill supposed to streamline the country's legislative process. The bill's critics argued it would give too much leeway to the prime minister.

Renzi's resignation could ultimately sweep Grillo's left-leaning and anti-establishment Five Star Movement party into power — and throw Europe into an economic and potentially political crisis. Grillo has for years advocated a referendum on Italy's euro zone membership status. Such a referendum would destabilize Italy's fragile economy and, particularly, the country's banks. After the release of the first exit polls Sunday evening local time, the value of the euro against the dollar immediately fell. 

After Sunday's referendum, Grillo appeared confident about the future prospects of his party, when he tweeted: “A lesson for everyone: you can't lie forever to the people without suffering consequences.”

On his website, Grillo argued that new elections should take place as soon as possible. “The regime's propaganda and all of its lies are the first losers in this referendum,” Grillo wrote. “Times have changed. The sovereignty belongs to the people again — and now we will really start to apply our constitution.”

Five-Star Movement activist and comedian Beppe Grillo celebrates after swimming across the Strait of Messina from Cannitello in Calabria to Messina in Sicily as he begins his election campaign October 10, 2012. Italian elections are expected to take place in spring 2013. REUTERS/Antonio Parrinello (ITALY - Tags: POLITICS ELECTIONS ENTERTAINMENT) Five-Star Movement activist and comedian Beppe Grillo celebrates after swimming across the Strait of Messina from Cannitello in Calabria to Messina in Sicily as he began his election campaign Oct. 10, 2012. (Antonio Parrinello/Reuters)

Despite strong differences between Grillo and Donald Trump — one is a comedic actor-turned-political activist; the other is a real estate executive turned novice politician-turned-president-elect — the two are now frequently being compared in Europe. The Italian comedian himself made such remarks in an interview after Trump's victory: “Our movement has some similarities,” he said. “We became the first political movement in Italy, and the media didn't even realize it.”

Similar to Trump's “drain the swamp” political message, Grillo has taken a strong anti-establishment and anti-corruption stance, accusing Renzi of preventing economic and anti-corruption reforms. The movement's five stars stand for “public water, sustainable transport, sustainable development, the right to Internet access and environmentalism.”

Above all, though, the party (which considers itself not a party but a movement), stands in opposition to the leaders who have governed Europe over the past few years, during which the continent struggled to deal with economic austerity. Italy has been particularly hard-hit, with a current youth unemployment rate of 27 percent.

Referring to German Chancellor Angela Merkel and European Commission President Jean-Claude Juncker, Gillo said in an interview with the Financial Times last year: “They have a kind of illness, it’s called alexithymia, which means difficulty recognizing the emotions of others: pain, pleasure, joy. … They don’t care if they have to put tens of millions of people into hunger to balance an account, it’s collateral damage. We’ve entrusted our lives to people who know nothing about life,” he said.

Especially in Northern Europe, Grillo's statements have raised worries over his use of populist rhetoric. Grillo “prides himself on his ridicule of the parliamentary system,” conservative-leaning German journalist Jan Fleischhauer wrote in a widely discussed article in 2013.

“Yet while his anti-establishment rhetoric sounds appealing, at heart it's actually anti-democratic. And very similar to that of an infamous Italian from the past,” Fleischhauer wrote, drawing a comparison between Grillo and former Italian dictator Benito Mussolini, the leader of the National Fascist Party.

Speaking to The Washington Post's Anthony Faiola in 2012, Grillo strongly rejected comparisons between him and fascist dictators. “They are calling me a populist, calling us Nazis, calling me Hitler, but they do not understand,” he said. “What is happening is that our movement is filling a similar space as the Nazis did in Germany or [nationalist Marine] Le Pen has in France. But we are nothing like them. We are moderate, beautiful people, and we are the only thing left standing between Italy and the real extremists.”

In Trump, Grillo appears to have finally found an appropriate leader with whom to be compared. Both became famous on television. They feel neglected by the media and by the political establishment. And both are considered similarly damaging in Brussels, Berlin and Paris.

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In Italy, a comedian is getting the last laugh