But this was a particularly wrenching issue for Irish voters, even for supporters of the measure.
The polls are open from 7:00am (0600 GMT) until 10:00 pm (2100 GMT) on Friday, with full results not expected until Saturday evening.
An exit poll from Irish broadcaster RTE poll indicated that about 72 percent of women voted "yes" along with about 66 percent of men.
The outcome of the case was a Supreme Court ruling that the government should legislate to explicitly acknowledge the right of a woman to access an abortion if she was suicidal, and to delineate precisely when, and how, a woman whose life was endangered through pregnancy, could access a termination.
If the amendment is repealed, government leaders plan to push a proposal to legalize abortion for any reason up to 12 weeks of pregnancy and up to six months in a wide range of circumstances. As it turns out, people are making the trip from all over the place - including Japan, Costa Rica, Sweden and Thailand - and they say it's worth the cost.
"I feel like I've waited all of my adult life to have a say on this", she said. Through my tears I read message after message of support, many expressing their solidarity with the 3,500 women a year who travel overseas for abortion access.
"This was the absolute reality", she said. "I am confident that Ireland will reaffirm the right to life on Friday!".
"Please vote yes on Friday!". Canvassing door to door in Dublin, it appears that people are fairly evenly split, with more upper-crust neighborhoods leaning towards "Yes" and middle-class neighborhoods leaning towards "No". But clergy members are not leading the referendum campaigns. He told the Associated Press that there are no rules for political campaigning on social media in Ireland.
Prime Minister Leo Varadkar called the result the culmination of a “quiet revolution.”
We need a clear message today that if you want change you have to vote "yes".
"This is devastating for the Roman Catholic hierarchy", said Gail McElroy, professor of politics at Trinity College Dublin. "They're no longer the pillar of society, and their hopes of re-establishing themselves are gone". "We are in Ireland to spread awareness of the biology and embryology of the developing fetus in the womb and that is a misunderstood mission".
The result caught most observers and voters off guard.
There has been a big surge in voter registration ahead of the referendum. "It really pulled a whole community together, this little person, and I wonder had that little person been opted out what would have happened", Mulligan continued. Prominent television shows are hosting lively debates in which abortion activists and pro-life advocates face off, with the nitty-gritty details of the violence of abortion being discussed in a way that would cause fainting spells over at the CBC. For instance, Martina Collender recalls establishing Waterford Pro-Choice in response to a case two years ago involving a young girl placed in a psychiatric ward after her request for an abortion was denied.
Corr, who has nearly 17,000 followers on Twitter, said: "As many were duped into believing the Lisbon Treaty would bring jobs and recovery, many are being duped into believing this referendum is about healthcare and choice, when it's really about bringing the lucrative abortion industry into Ireland". In 2011, Mellet was forced to choose between carrying a dying fetus to term in Ireland or to travel overseas for an abortion.
Simon Harris, Ireland's Minister of Health, said a bill would be written this summer. "All of us have underestimated our country", she said before breaking down in tears.
The final results were 1,429,981 people voting in favour fo a repeal on the country's strict abortion laws, and 723,632 people voting against. Abortion is still a highly personal issue for many voters, shaped by personal experiences such as miscarriages or fetal abnormalities.
Within a generation, all of that has changed, bringing the majority-Catholic nation of about 4.8 people into line with the rest of Western Europe.
"We will oppose that legislation", he said. "Go over to England and get it done there, not here". Although it has not been the center of campaigning, the question of how Irish women have been treated historically - from the use of symphysiotomy, a primitive form of obstetric surgery, to the scandal of unmarried mothers who endured forced labor in the "Magdalene laundries" - has informed opinions here.