Marian Ryan voted for Sinn Féin for the first time in her life because she could not bear the prospect of the same old crowd running another government. “We need change,” the 63-year-old Dublin childminder said on Monday. “We needed to get the muppets out.”

She made up her mind the moment the election was announced three weeks ago and cast her vote on Saturday with a giddy hope she was closing a dustbin lid over the taoiseach Leo Varadkar, his ruling Fine Gael party and the other establishment parties that had taken turns ruling Ireland over the past century.

“They’re all in it for themselves,” she said. “I want a government for the people.”

James Kealy, 63, a retired glass worker, had an earthier reason for why he and so many voters decided to take a chance on a party – the IRA’s political wing during the Troubles – once deemed untouchable. “Everyone else has made a bollix of it so give them a chance.”

As counting of votes continued, confirming Sinn Féin’s breakthrough as Ireland’s most popular party, with 24.5% of the first preference vote, people across central Dublin willingly lingered on cold, icy streets to condemn the status quo and voice hope for change.

More public housing, a rent cap, additional hospital beds, better pensions, fairness and dignity, Sinn Féin’s to-do list – should it negotiate a deal with other parties and get into government – went on and on.

Unless prompted, few mentioned Northern Ireland, Irish unity or Brexit. This was an election decided by tangibles: a ragged tent under an overpass, a sibling unable to pay rent, an aunt waiting on a hip operation. “You go to bed at night thinking ‘oh those poor people out on the streets’,” said Ryan.

Things that Varadkar had hoped would give him another term – plentiful jobs, the European Union’s highest growth rate, diplomatic successes – felt remote, abstract. What’s the use of switching jobs if you still can’t afford a mortgage? Why worry about Brexit if you can’t pay car insurance?

Aisling Caulfield, who voted for Sinn Féin in Dublin - her first ever vote in an Irish election. Photograph: Rory Carroll/The Guardian

Aisling Caulfield, 49, walking her dog down Pearse Street, said she voted for the first time in her life out of a sense that this election mattered. “Sinn Féin – they want more, they want to do more.” She hadn’t planned to vote, it was impulse.

It helped that Sinn Féin’s leader, Mary Lou McDonald, 50, is articulate, a Dubliner, a woman and untainted by any paramilitary links.

During a walkabout on Moore Street, a trader’s market, McDonald was asked whether she will be the next premier. “I may well be the next taoiseach, yes,” she said. Just weeks ago both question and answer would have been ridiculed, but that was another Ireland.

For every voter familiar with Sinn Féin’s policies – increase tax on the rich, build public housing, ramp up spending – others backed the party simply because it embodied change, a precious label that in previous elections affixed to, and benefited, the Greens, Labour and other parties.

Fianna Fáil, the main opposition party, forfeited the change vote by having supported Varadkar’s administration in a confidence-and supply deal.

James Alden, a Dublin hardware shop owner who voted for Sinn Féin and Fianna Fáil. Photograph: Rory Carroll/The Guardian

“Fianna Fáil and Fine Gael needed a kick up the arse,” said James Alden, 47, a hardware shop owner who nevertheless gave preferences to both Sinn Féin and Fianna Fáil. “And Sinn Féin were rattling cages that they weren’t before. It’s happening across Europe – parties that were see as troublesome or too far left are being given a look.”

Some voters appear to have been emboldened by opinion polls that detected the surge and weakened any taboo about voting for a party previously led by Gerry Adams. It was a startling, fickle shift from last year when voters deserted Sinn Féin in local and European elections – a sign of how volatile Irish politics has become since the the financial crash a decade ago.

On the day of the “Mary Lou McDeluge, sweeping all before her” as the Irish Times put it, it was easy to forget that Sinn Féin is the party with the highest negative rating, 36%. Its role in the Troubles cannot be wished away, said Hilary Hughes, 57, a retired care worker. “They did some dreadful things.”