On Election Night here in Ireland, we all watched in shock as the old political order was upended and a radical third party, Sinn Fein, became the new rising force in Irish politics.

A few decades ago, Sinn Fein (pronounced “shin fane”) was a minuscule group known—and shunned—for being the political arm of the Irish Republican Army. In 1992, Sinn Fein leader Gerry Adams was the lone member of his party in the Irish parliament; that year, they received a paltry 1.6 percent of the vote. Once the Good Friday Accords were signed, ending the long conflict in Northern Ireland, many thought Sinn Fein might disappear altogether, having seemingly lost their reason for existing.

Instead they put all their energy into rebranding themselves as Ireland’s political alternative. Only 10 years later, with the stigma of the Troubles having faded in public memory, their support had quadrupled to 6 percent of the vote. After the economy crashed in 2008, that share doubled, then doubled again. This year’s election saw Sinn Fein in an almost three-way tie, as the two formerly major parties declined. Those major parties ran for every seat yet saw fewer than a quarter of their candidates win, while almost all of Sinn Fein’s candidates were elected. They could have done even better had they run for more offices, and their surge took even them by surprise.

How this happened

Ireland’s elections have a number of admirable features. First, we get to elect multiple officials to represent each area, often from many parties, so voters can test out how responsive each party is to our needs. We rank our choices from first to last, so if no one gets enough votes out of the gate, second choices are taken into account, then third choices, and so on. Sinn Fein won most of its votes on the first round of counting, indicating they were the first choice for an enthusiastic minority, while the comeback of the old-guard parties later in the counting indicates that they remained backup, reluctant choices.

As with most Western countries, Ireland has a parliamentary system; voters elect representatives from different parties to the Dail (parliament, pronounced something like “Doyle”) who then hammer out a government. Since Ireland won its independence a century ago, this has never been a problem—the two major parties have basically taken turns holding the reins of power, with the occasional third party slipping into a comfortable coalition.

Fianna Fail (pronounced “Finna Fall”) and Fine Gael (“Finna Gale”) originally emerged out of the two sides of Ireland’s civil war. They quickly settled down and became staid, respectable institutions. Both were packed with career politicians; both were pro-business and center-right by European standards (until now, Ireland has been unique in Europe in that it has no major left-wing party). As Ireland modernized, both became pro-globalization and pro-EU, and when the culture shifted tectonically towards gay marriage and abortion, both suddenly claimed they’d always been in favor of such things.

Fianna Fail happily rode the wave of the Celtic Tiger, that economic boom that transformed Ireland from one of the poorest Western countries to one of the richest, and saw immigrants flood in until one out of every eight people was foreign-born. But when the global economy crashed in 2008, Ireland crashed harder than most countries—relative to its small size at least—and it soon had to be bailed out by the European Union and the International Monetary Fund. The Irish people were outraged, as they lost the economic sovereignty their grandparents had fought a revolution to attain. Fianna Fail took the blame: in the next election. they fell from first to fourth place, the greatest plunge of any party in Irish history.

Fine Gael won that election, of course, but their support was short-lived. They could not do much about the austerity programs that had been imposed on Ireland, and when they tried to introduce new taxes, thousands protested and millions refused to pay until the government just gave up. Soon support for both major parties stood at record lows, and Sinn Fein was there to fill the vacuum.

It’s tempting to reach for easy explanations—say, to compare this to other populist uprisings in Europe. And certainly Sinn Fein taps into a nationalist pride, filling a need for a people who have lost much of their religion, traditional culture, and economy. Yet populist waves in other countries have been classified, however imperfectly, as “right-wing,” while Sinn Fein is socialist. Nor is there a strong anti-migrant component to their agenda—Ireland has the largest immigrant population in Europe, but most are other Europeans or Americans like myself—culturally similar enough to integrate.

Other pundits are already blaming the election on Brexit, which took place only a few weeks earlier. But according to polls, few Irish list that as a top concern. Nor can Sinn Fein’s rise be seen as a straightforward backlash against recent cultural changes, like abortion and gay marriage. Sinn Fein enthusiastically supports these things, and the more socially conservative minor parties that opposed them failed on Election Night.

Polls instead tell a different story: the younger Irish voters are, the more likely they are to vote Sinn Fein. The party won just 12 percent of the vote among those 65 and older, and almost three times that among voters 18 to 24; for the traditionally dominant parties, the numbers are reversed. Fianna Fail and Fine Gael have become the political versions of newspapers and land lines, with Sinn Fein as Snapchat and Instagram.

Voters indicated that their main concerns were economic. Ireland looks prosperous on paper, but much of its growth has been as a tax haven. Foreign direct investment looks high, but an IMF study found that three quarters of that investment was simply corporations evading taxes by moving assets around, little of which reaches the people. About 80 percent of Irish make less than €50,000 a year, yet Dublin is one of the most expensive cities in the world to live in.

Younger voters are more likely to be unemployed and unable to afford a place to live—and Sinn Fein promises sweeping changes that will make Ireland affordable again. Its voters are like Bernie Sanders supporters in the United States, but with the added gravitas of patriotism and rebel chic.

There is another reason, of course, that younger voters are rallying around Sinn Fein: they don’t remember the Troubles. This despite the fact that the conflict in Northern Ireland ended only 20 years ago, hardly less distant than the September 11 attacks. The Troubles killed 3,800 people, mostly in Northern Ireland, a tiny state of 1.8 million. That death toll, scaled up to the size of the U.S., would empty Boston.

Nor is this past merely academic. One Sinn Fein official elected last weekend was a former IRA terrorist who spent years in prison for building a bomb. If a Sinn Fein coalition takes the helm of government, we could see a Sinn Fein minister for justice, police officers answering to an official whose group tried to assassinate police officers.

Even more complicated would be the post-Brexit situation. The UK is Ireland’s main trading partner, and if Sinn Fein takes power, they would be undergoing delicate negotiations with the very people they were created to oppose. They would also have to broker a solution to the Irish border when their raison d’etre is to have no border.

What comes next

The two old-guard parties, which used to garner close to half the seats in the Dail, received fewer than a quarter apiece this election; Sinn Fein received the same, with the remaining quarter taken up by smaller parties and independents. Now this fractured parliament must stitch together a coalition, but no one has anything close to a majority, and the major parties have sworn never to work with Sinn Fein.

The most likely outcome is that Fianna Fail, Fine Gael, and a number of third parties and independents will form a “super-coalition” to shut Sinn Fein out of power. It could work for the moment, but it would likely do nothing to stop their rise, and it would enrage their enthusiastic supporters.

Another possibility is that one of the two old parties swallows its pride and goes into coalition with Sinn Fein, though any party that does this would lose many supporters on principle. Finally, there is the possibility Sinn Fein hopes for, which is the creation of a far-left coalition with most other third parties and independents. But it’s doubtful they could get all those people to work together or agree on much of anything.

Whether or not Sinn Fein takes power this time, it is likely they will do so soon. Many of my acquaintances here have welcomed their platform of economic reform, reasoning that the realities of governance will force them to rein in their radicalism. Maybe they’re right; maybe Sinn Fein will excel once in power. After all, both Fianna Fail and Fine Gael began as paramilitary groups a century ago.

Maybe other third parties in Ireland—like its right-wing and pro-life parties—will tap into the same populist enthusiasm currently given to Sinn Fein. Or perhaps the old-guard parties will realize their mistake and change course to meet public demand, rebooting their relationships with their constituents. The situation here is politically unstable, but everyone is feeling the public pressure for change, and a great deal of good could come out of Sinn Fein’s rise.

But Sinn Fein has left a great many skeletons behind it, and in very recent memory. At the historic moment of Brexit, which has thrown Northern Ireland issues into question again, many Irish voters rallied behind the group that played a key role in the violence there. According to news reports, supporters even struck up pro-IRA chants at victory parties. We can only hope that none of this indicates a return to the violence of the past. Voters are playing a risky game.

Brian Kaller has written for Front Porch Republic, First Things, The Old Schoolhouse, Mother Earth News, and Grit. He writes from his home in rural Ireland and blogs at www.restoringmayberry.blogspot.com.