Last summer, Erik Martin, the general manager of the link-sharing site Reddit, whose job requires him to oversee online conversations about everything from My Little Pony to Islamic State propaganda, noticed something strange. A Spanish political party that he’d never heard of was using the Web site to organize. “We’ve never seen anyone use Reddit as an organizing tool, not like this,” he said. The party, called Podemos (We Can), was only a few months old at the time, but it had created a subreddit—in effect, a party home page hosted by Reddit—with more than two thousand subscribers and significant traffic. About two hundred people were visiting the page at any given time, and there were a million page views in the month of July alone. “This was all in a market”—in southern Europe—”where Reddit is not even that popular,” Martin said. On the party’s page, an array of filters directs users to caches of videos, proposals, debate topics, and news. There are “digital assemblies” (a sort of virtual plebiscite), “Ask Podemos” (question-and-answer sessions with party leaders), and “Podemos Plaza” (a freewheeling discussion via message board). The other day, one user linked to a grim news item meant to spawn a local protest initiative: the municipal government of Madrid had dedicated a plaza to Margaret Thatcher.

When Martin and I spoke over the summer, he admitted that he didn’t know much about Podemos: Was it a serious party with serious prospects or was it a group of idealistic interlopers? That question has been on the lips of Spaniards for months.

Elections for the European Parliament are generally a somnolent affair—low on turnout, high on cynicism, slim on newsworthiness—but last May Podemos upended the political landscape. Just six months old, the party won 1.5 million votes, or eight per cent of the over-all vote count, and gained five seats in the European Parliament. Podemos’s rise drew votes away from the mainstream Socialists, which meant that, for the first time in three decades, the two major parties—the left-of-center Socialists and right-of-center Partido Popular—could not cover a majority of voters between them.

Podemos promoted itself as a populist alternative, using slogans that drew on a familiar international vocabulary with overtones of Occupy and of the European anti-austerity movement: “We Are the 99%”; “The Debt Is Illegitimate”; “The Two-Party System Is a Thing of the Past.” Podemos’s leader and figurehead, a political-science professor named Pablo Iglesias, told the press, from the steps of the European Parliament: “All that’s left in Europe is a political élite that kneels before the financial powers … Some Europeans don’t want to be colonies of the Troika.” Recent austerity measures are largely the Troika’s doing, and unemployment has spiked in Spain, Portugal, Italy, and Greece. This has made national politics seem like a futile affair, with local politicians answerable to Berlin and Brussels on economic policy. The sworn mission of Podemos is to restore politics to the people. “We propose a grassroots politics—that is, to do away with the establishment parties and, from there, put in motion a method,” Iglesias has said.

For Podemos, the method is the message. If you scroll through the party’s Reddit page or listen to its spokesmen on the radio, you’ll get a litany of fair-minded gripes about austerity and political corruption and malfeasance in the banking sector. What you won’t hear, at least not yet, is a specific policy agenda. Podemos’s success at the ballot box depends on keeping party pronouncements flexible and all encompassing in the run-up to next year’s elections. (Some recent polls show Podemos as the third-most-popular party in Spain.)

Earlier this month, Podemos began a formal process to hone its identity further by hosting Reddit debates and referendums on the defining features of the party: How should the hierarchy and structure be organized? Who should lead the party? (Its current progenitors and spokespeople are placeholders, pending formal primaries.) What should be its official mission statement, and what sorts of public policies should it angle for? In mid-October, an actual assembly will be held in Madrid to winnow the proposals circulating online and to set up discrete votes toward a charter. By November, the party will look somewhat less ragtag and more like a more typical party—that is, with a leadership structure and a platform in place.

Until then, Podemos will be the world’s first Reddit party. Debates and online votes will shape the party as it stands for election in 2015. Reddit works by simple up-or-down votes: a registered user posts something and other users give it a thumbs-up or a thumbs-down. A particular post’s prominence on the site rises or falls by these ratings. It’s the direct democracy of Web content, with all the attendant costs (herd mentality, Internet rabble, scant checks on the integrity of content) and benefits (organically popular, egalitarian, full of surprises). Each exchange on the Podemos’s subreddit page—whether a back-and-forth with a party leader, a proposal, a particular line of debate, or press clip—is scored by Reddit users, and this helps to determines whether or not it is absorbed into the party’s project. With this model, Podemos is sounding out ideas about itself and about its world.

A few weeks ago, I called Eric Labuske, a twenty-six-year-old from Madrid who is a member of Podemos. The party’s structure is an agglomeration of committees, or working groups, with different areas of focus; some are thematic and others are more administrative (logistics and production, participation, international relations). Labuske is part of the “participation team,” so the administration of the party’s Reddit page is his charge.

The rough organization of Podemos translates to the Web fairly naturally, he told me. So-called circles of Podemos supporters have cropped up throughout the country, organized most often by region (neighborhood, municipality) or by profession or orientation (engineers, Web designers). These circles debate whichever issues are of particular importance to them. It’s difficult to say how many people form any given circle—sometimes the circles actually meet in person—but now they exist on Podemos’s subreddit page. The model is a holdover from a protest movement, launched in 2011, known as 15-M, for the day, in May, when demonstrators took to the streets to protest political and economic deadlock. These protests began as simple street demonstrations, organized on social media, and grew into a broader and more sustained cri de coeur. “Spain’s was probably one of the largest and best-organized protest movements in the world,” the economist Joseph Stiglitz told me recently. He had gone to meet with Spanish protestors at the time, in Retiro Park, in Madrid. “Spain was very influential for Occupy Wall Street. What you saw in Spain was that this was clearly not the fringe of society,” he said. Podemos culls its ranks from these so-called indignados and reflects that broad demographic: mostly young people, almost exclusively lefty, and uniformly disgruntled by the major political parties.

Over time, the 15-M movement became an umbrella group for hundreds of local chapters that held weekly assemblies in cities across Spain. Some of these groups were nimble and essential—in one area of Madrid, for instance, a neighborhood assembly prevented authorities from carrying out home foreclosures—others, less so. The biggest challenge was finding a way to streamline the discussions. Assemblies went on for hours, proposals were debated ad nauseam. “15-M showed us that sometimes an assembly wasn’t the most effective way of achieving consensus and reaching majorities,” Labuske told me. “Internet tools have helped improve this.”