It’s the vote that could either plunge Italy into a fresh crisis and threaten its future in the eurozone, or hand the country a once-in-a-generation chance to streamline government and speed up lawmaking. But why is the referendum important? Firstly, the reforms are significant, so significant, some have argued, that if they are approved by the electorate, they would represent the birth of Italy’s third republic. Secondly, Italian PM Matteo Renzi has staked his future on the vote, saying he would quit if he is unable to secure a victory for his constitutional changes. Italy is somewhat of an anomaly in western Europe, because it’s one of the only countries where the deputy chamber (lower parliament) and senate serve the same function. The reforms propose drastically diluting the power and size of the senate and replacing elected senators with representatives from the regions. The latter will comprise around 100 people, either mayors or members of regional councils. The other main pillar of the reforms is to rebalance the power of the regions, bringing more areas under the control of central government and removing any duplication. Italian Prime Minister Matteo Renzi resigned on Sunday night after suffering a crushing defeat in a referendum on constitutional reform. His fall ushers in a period of political uncertainty for Italy, not a new thing for a nation that has had 65 prime ministers in almost as many years, as it searches for a new government, possibly holds early elections or both. The unexpectedly resounding rejection of the proposed electoral reforms is in one sense a vote for the status quo, another Italian specialty. But it raises uncomfortable questions for EU leaders about the enduring strength of populism across the Continent and the future of the euro. The 41-year-old center-left leader turned a proposal to streamline the lawmaking process and centralize more political power into a referendum on his own rule that he said he hoped to use as a mandate for reform. Renzi’s opponents won almost 60 percent of votes and 17 out of Italy’s 20 regions, according to preliminary results, while his Yes campaign managed just 40 percent and three regions. High voter turnout of more than 66 percent made it an even more conclusive defeat for the former mayor of Florence. Renzi had promised to quit his position if he failed, and an hour after the exit polls came out, he did. “I lost. In Italian politics, no one ever loses,” he told a news conference just past midnight. “But I am different. My political experience in the government comes to an end here.” “The No won in an extraordinarily clear way. Now it’s up to them to come up with concrete proposals and reforms,” Renzi said, adding that he would formally advise President Sergio Mattarella of his decision on Monday, after saying goodbye to his cabinet. As head of state, Mattarella will now be in charge of calling new elections and/or setting up a temporary technocratic government. It may not all be over for Renzi. Though it is unlikely in the face of strong opposition calls for early elections, Mattarella could still turn down Renzi’s resignation and ask him to go before parliament to clarify whether he has the majority needed to form government. If Mattarella accepts the resignation, Renzi, who retained his role as PD leader, may yet manage to reshuffle cabinet and re-form government, potentially with Economy and Finance Minister Pier Carlo Padoan as prime minister. In the event that, as some analysts predict, Padoan is rejected by the opposition, the new premier could be an institutional figure like Senate President Pietro Grasso. If that fails, Italians may need to go back to the ballot box for an early general election.