how did the ira rig the irish elections in the year 2020

Well there's personation.
One guy voting loads of times.
I remember an associate of former Prime Minister Charlie Haughey being convicted of that back in the 1980s.
Then there's stuffing ballot boxes with pre entered votes and merging them with legitimate votes.
That old gag.
The specialty of Cosa Nostra in America.
Maybe they showed the IRA how to do it.
Then there's fraud via computer.
Vladdie Putin's favourite method.
Should be some opportunities for that.
Finally and most importantly there's the active subversion of counting centres.
You don't need them all.
You just need a few.
And in the targetted counting centres, the subversion must be organised and endemic. You need a lot, most or all of the personnel working for you.
Best to infiltrate an agent at Managerial level.
Get him in a position to recruit fellow travellers.
They must be able to alter votes without looking over their shoulders.
They must be able to fill in blank voter slips without worrying about who's watching.
They must be able to jerrymander the transfers of the surplus votes which arise  in the Irish electoral system selectively to Sinn Fein without thinking someone's going to spot the shenanigans.
So in the key subverted counting centres, there must be more mafiosi than there are honest people.
Do that and you get results like Sinn Feiners topping the polls everywhere and winning seats in constituencies like Wexford that have never ever before returned a Sinn Fein candidate.
It's also a good idea for some of your candidates to book holidays for the week of the election so that they too can act surprised at the unprecedented results.
It's the perfect blagg.
They did it.
Last word to newly "elected" "parliamentarian" David Cullinane of Sinn Fein: "The couldn't break us. They couldn't break the hunger strikers. They couldn't break Bobby Sands. Up the Republic. Up the Rah. Tiocfaidh ar la."
Quite.