Jean-Luc Mélenchon , an insurgent left-wing candidate for France’s presidency, is surging. His candidacy, organized under the newly-established party La France Insoumise (“Unsubmissive France”) has gone from a quixotic bid to a viable challenge in just a few months. Railing against growing economic inequality, participation in foreign wars, and political corruption, Mélenchon has skyrocketed in the polls from distant fourth to within a hair’s breadth of the frontrunners. (This rise has been accompanied by the release of a web-based video game called “Fiscal Kombat” where Mélenchon fights corrupt politicians and bankers.) The Financial Times demonstrated his surge through an aggregation of French national opinion polls:

Source:Financial Times

Because no candidate is expected to get a majority of the vote, the national election on April 23 is, for all practical purposes, an elimination round. The top two vote-getters will then compete in a run-off on May 7. So in order to win the presidency, Mélenchon has to oust either centrist Emmanuel Macron or far-right Marine Le Pen, both of whom are running slightly ahead of him and conservative François Fillon. Many have drawn comparisons between Mélenchon and Bernie Sanders. Raquel Garrido, a spokesperson for Mélenchon’s campaign, told Jacobin Magazine in early April that, like Sanders, Mélenchon is embracing a populist platform that seeks to speak to every portion of society, not just the traditional left. “I think we are similar to Bernie Sanders in that way, who rarely spoke about ‘the Left,’ but about the people against the 1 percent or the billionaire class,” she said. Mélenchon’s supporters have circulated a meme on social media comparing Le Pen to Trump and Macron to Clinton. “To beat Trump it would have been necessary to support Sanders,” it reads. “Let’s not make the same mistake!”

But there is a major difference between Sanders and Mélenchon. The American chose to run within an existing political party, while the Frenchman seeks to compete against them. That’s why, unlike Sanders, Mélenchon is still in the running at this late stage, as the voters are souring on the candidates of the far-right and co-opted center. Prior to announcing his bid for the White House, Sanders had to choose between running as an independent, as he did in his Senate races in Vermont, or within the Democratic Party. He openly struggled with that choice in an interview in March of 2014 with The Nation. “There is today more and more alienation from the Republican and Democratic parties than we have seen in the modern history of this country. … In that sense, running outside the two-party system can be a positive politically,” he noted. “On the other hand,” he went on, “given the nature of the political system, given the nature of media in America, it would be much more difficult to get adequate coverage from the mainstream media running outside of the two-party system. It would certainly be very hard if not impossible to get into debates. It would require building an entire political infrastructure outside of the two-party system: to get on the ballot, to do all the things that would be required for a serious campaign.” For those same reasons, when Sanders lost the Democratic presidential primary to Hillary Clinton, he chose not to keep running as an independent, even though he had long argued that he had a much better chance of beating Donald Trump than Clinton had. If it was easier in the U.S. to run outside the two-party system, Sanders could more easily have run as a third-party candidate, and conceivably could have made an argument as election day approached that Clinton would have been the “spoiler” — the candidate draining votes from him, rather than the other way around. Mélenchon is probably looking at the ruling Socialist Party candidate Benoît Hamon — polling at eight percent — and wondering if Hamon’s voters will prevent him from going to the second round of voting. Mélenchon was once a junior minister in the the Socialist Party, which is France’s version of the Democrats. But as the Socialists moved towards neoliberalism, he left the party and for a long time was in the political wilderness. When he announced last year that he would be challenging the mainstream parties in France’s presidential election, he was considered a non-factor. Mélenchon is not only an advocate for left-wing policies like higher taxation, but also for remaking the French political system itself. There are many ways countries elect their national parliaments, but they can be roughly grouped into two categories. There’s the system that the United States, Canada, the United Kingdom, and a few other countries use, which is based on apportioning seats by single-member constituencies. Each district is winner-takes-all, so theoretically one party could win 51 percent of the vote in every district, and 100 percent of the parliament. That creates a powerful inducement for gerrymandering — and it also makes it particularly hard for new parties to get a toehold. In practice, this leads to domination of the political system by just a few parties, with voters typically cluster into two parties, both vying to top the other one. The alternative is called proportional representation (PR). Under a PR system, the electorate casts its votes nationwide for whatever political party they choose, and then seats are distributed by percentage. You don’t have to win the majority of votes in any one geographically-bound district to enter the parliament. This allows for the rapid growth of minority parties, and more political diversity. So, for instance, in PR-using Israel, there are 10 political parties in the Knesset. PR-using Sweden has eight parties represented. Justin Trudeau, Canada’s Liberal Prime Minister, won election in 2015 with a promise to shift Canada towards a proportional system (a promise he soon turned his back on). Canada’s The Globe & Mail made a video explaining how PR would work: