In the last 68 years, Italy has held 17 general elections and a few referenda. But only three times has an Italian vote claimed center stage internationally: in 1948, when the choice was between the West and communism; in 1976, when voters faced a similar choice, between the Christian Democrats and Enrico Berlinguer’s “Eurocommunism”; and now, with the upcoming referendum on constitutional reforms.

The implications of the upcoming vote are enormous. Prime Minister Matteo Renzi has staked his political future on the vote, pledging to step down (though not immediately) if the reforms are rejected. Such an outcome that would irreparably weaken the center-left government coalition as well: Renzi’s Democratic Party (PD) is already roiled by infighting over the reforms. In fact, the PD may not be able to avoid a split even if the vote goes the prime minister’s way.

A defeat for Renzi will be read as a victory for Italy’s two major populist parties: the Lega Nord and the larger Five Star Movement, led by the comedian Beppe Grillo. The two parties are not allied, but both are nurtured by anti-establishment sentiment and favor “national solutions” to Italy’s problems – beginning with a return to the Italian lira.

If Renzi is defeated, Lega Nord and the Five Star Movement could join forces to support a new government and hold a new referendum – this time on the euro. If Italy – one of the world’s largest public debtors – decided to go it alone, the entire European project could be dealt a mortal blow. In the age of Donald Trump and Brexit, that outcome is far from unthinkable.

The issue at stake in the referendum is not inconsequential, but it should not decide the fate of Europe. Italians will vote on whether to strip the Senate (the parliament’s upper house) of two-thirds of its members and much of its legislative authority, making it merely a talking shop akin to Germany’s Bundesrat, and return some of the regions’ powers to the central government.

Changes like these have been discussed for 30 years. The lack of movement could benefit Renzi, if voters conclude that they should not waste such a rare opportunity to do something to reform their sclerotic system. President Sergio Mattarella is impartial, but he would prefer that the reforms go forward. His predecessor, Giorgio Napolitano, is also strongly in favor of the reforms, which he sayswould be “great news for Italy.”

But the reforms have also faced stiff opposition. Some state institutions dislike the idea of delivering more powers to the executive branch; magistrates, for example, fear a loss of judges’ extensive and unchecked powers. Then there are the new populists, several PD old-timers, and plenty of other establishment figures, including several former members of the constitutional court, who generally fear change. Former Prime Minister Silvio Berlusconi, ever the opportunist, is also opposing the reforms.

The opposition, as usual, benefits considerably from its simple message. To vote “no” is to vote against the “system” and all of its corruption. Who is not against corruption? Add to that rising Euroskepticism, and the result is an intoxicating political brew. Opinion polls now indicate a 5-6-point majority for No, with 20% of voters still undecided.

If a general election follows the referendum, Grillo will be running neck and neck with Renzi’s PD. Given the huge premium accorded to the winner by Italy’s new electoral law (Renzi was sure he would be the one to benefit), such a prospect is truly frightening.

Grillo – much like Lega Nord’s Matteo Salvini – has scant political experience, little knowledge of European history, few refined arguments, and no credible vision for the future. He blames Europe for Italy’s mistakes, such as piling up massive public debt, which now amounts to 132% of GDP. And he makes unfeasible promises, such as a guaranteed income for all citizens without other means.

Juan Perón, the consummate populist, proved just how flawed such giveaways can be when he took a similar tack in Argentina. And that is not even the only Argentinian mistake Grillo may be set to make. He also supports the Argentinian model of dealing with the debt by defaulting on it. It is such an absurd proposition – Italy has never defaulted, though it did, under Mussolini, try to go its “own way,” with disastrous results – that one wonders whether Grillo is capable of distinguishing between policy and comedy.

As in the United Kingdom and the United States, change is the magic word in Italy today. Nobody wants to be against change. Instead, opposition to reform is framed as support for better reforms. Don’t just change the constitution, the No campaign implores voters: change everything! As in Giuseppe Tomasi di Lampedusa’s great novel Il Gattopardo (The Leopard), changing everything could be just the way to keep it all the same. That is the last thing Italy needs.