Saturday's election in Ireland is the third since the dramatic financial collapse in 2008, and in many ways the political fallout from the 2010 EU-IMF arrival is still being played out. The 2011 election saw the near-wipeout of the centrist Fianna Fail rulers, who had been the largest party in every Irish parliament since the 1930s.

In their place came the center-right Fine Gael, whose five years of austerity led to electoral losses in 2016 and a modest rebound for Fianna Fail. That inconclusive election led to a novelty in Ireland: a confidence-and-supply arrangement where, in exchange for policy concessions, Fianna Fail abstained on major parliamentary votes and allowed Fine Gael to govern with a small cohort of non-party lawmakers.

That deal was only supposed to last for 2 1/2 years, but has endured for nearly four, solely because of Brexit. The elephant in the room is a possible hard border with Northern Ireland.

Read more: The Irish border — what you need to know

Brexit, homelessness, health crisis

Brexit aside, there are serious domestic problems. Home building ground to a halt during the financial crisis, leading to record property and rental prices, and record homelessness (nearly 10,000 were without a permanent home in December 2019).

At the same time, Ireland's health sector is creaking: December 2019 also saw an all-time record in hospital overcrowding, with new records for patients awaiting treatment on trolleys in lieu of a permanent bed. At any moment of the day, there are dozens of patients in the emergency wards of Irish hospitals who have been on trolleys for over 24 hours awaiting admission.

It is against this backdrop that the nationalist Sinn Fein party has suddenly roared into contention. The final nationwide opinion poll earlier this week gave the party a 25% share of the vote, versus 23% for Fianna Fail and 20% for the incumbent Fine Gael.

"The other two have ruined everything," one voter told DW on a street in Tallaght, a major suburb of Dublin. "Why not give someone else a go?"

In some sense, this is hardly surprising. Poll after poll confirms there is an evident appetite for "change" and dissatisfaction with Prime Minister Leo Varadkar's outgoing administration. Middle-ground voters are now seeking alternatives.

Sinn Fein has enthusiastically embraced a socially liberal platform, losing some conservative supporters but winning plenty more over its positions on gay marriage and abortion (a stance that, faced with the Democratic Unionist Party's opposition, contributed to the three-year suspension of devolved power-sharing government in Northern Ireland). This in turn has made it a more viable option for left-leaning voters.

Read more: Brexit drags up Northern Ireland's dark past

A unified Ireland?

Brexit itself may also have become Sinn Fein's perfect storm: Not only has it locked the two larger parties into an extended problematic marriage, but it has also left the prospect of a United Ireland looking far less remote. Northern Irish voters chose Remain in the 2016 referendum but are now outside the EU anyway. Faced with the choice between two unions — the UK or the EU — many north of the border would choose unity with Ireland. Unity is Sinn Fein's raison d'etre; already sharing power in Belfast, the party promises to hold a unity referendum within five years if it gains control in Dublin.

The Republic's electoral appetite for an extensive reintegration is not quite so strident, though. "How would we pay for that?" one voter asked DW. "Sinn Fein are promising all these tax cuts now, but what happens if we take the North back in again? It costs England billions of pounds to keep that place going already. We don't have that money."

Troubled legacy

Northern Ireland's difficult history remains a complicating factor for Sinn Fein, however. The leadership of Mary Lou McDonald, a Dubliner who replaced veteran Belfast leader Gerry Adams in 2018, has given the party a facelift and helped it to shed the previous label of being "the political wing of the Irish Republican Army (IRA)."

Read more: Northern Ireland's New IRA: What is it? 

But the hangover from paramilitary violence remains; older voters with clearer memories of Northern Irish violence are more reluctant to forgive Sinn Fein's IRA justifications, which the two historically larger parties cite as grounds to exclude it in any coalition.

Equally, the party faces accusations of shifting positions to follow public mood. It has vocally embraced the support of the EU in protecting Northern Ireland's interests after Brexit, yet has opposed each of the previous EU treaties and campaigned against them in referendums. It now welcomes foreign firms to Ireland (once appropriately taxed) but previously demanded an increase in its generous 12.5% corporate tax rate. It was a vocal supporter of the 2018 abortion referendum, but only after members voted to change its policy three times in the four previous years.

Read more: Ireland 'Yes' campaigners stunned by margin of victory in abortion referendum

Ironically, the party's meteoric rise has surprised even itself: It is fielding only 42 candidates to fill Ireland's 160 parliamentary seats, and its success at the expense of other left-wing parties may make it impossible to build a governing bloc. Meanwhile, the mechanics of Ireland's electoral system — where 39 constituencies elect between three and five lawmakers each, through a single transferable vote — could yet see Fianna Fail return with up to 60 members of parliament, despite a smaller share of the popular vote.

Be that as it may, Sinn Fein is now poised to recast Ireland's political dynamic and install itself as a third large party in what has historically been a two-party system. Its parliamentary representation may be smaller than its popularity would reflect, but could well be enough to force its way into a coalition despite the protestations of the establishment parties.

Whether in government or opposition, 2020 will be the election that sees Sinn Fein fundamentally break the mold of Irish politics.