Pending an analysis based on detailed breakdown of the turnout, here’s what likely helped make the difference.
Turnout was extremely high
We are still waiting for final figures on turnout. It appears clear, however, that electoral turnout was closer to the levels expected in a general election, than the usual levels for referendums (which are substantially lower). There was a 2 percent increase in the number of registered voters, with a late surge suggesting that many people registered to vote precisely so that they could participate in this vote.
Nearly universal support among the major political parties
All the major political parties urged a yes vote, including traditionally conservative parties such as Fine Gael (the main party in government) and Fianna Fail (which has been greatly weakened, but which has traditionally been the party of Irish rural conservative Catholics). Fine Gael initially did so with some misgivings, but agreed to a vote after Ireland’s Constitutional Convention recommended one. Its enthusiasm increased as it became clearer that gay marriage was a popular issue, and the Fine Gael Minister for Health, Leo Varadkar, came out as gay in January of this year, helping to give political impetus to the pro marriage equality campaign. Enda Kenny, the Irish Taoiseach (prime minister) spoke candidly in public about the personal journey he had made in coming to accept the need to change the constitution to allow a more inclusive understanding of marriage.
Fianna Fail also came out in favor, and although more Fianna Fail supporters opposed gay marriage than the supporters of any other political party, an older Fianna Fail politician, Pat Carey, was moved to come out as a result of the campaign. Irish left leaning parties were, unsurprisingly, more unequivocal in their support for gay marriage. The Labour Party, which is the junior party in the government, will be especially happy with the result, which it had made a major priority during coalition negotiations.
There were few opponents in Parliament to gay marriage. Non-party member of the Irish Parliament Mattie McGrath expressed his disagreement but did not campaign on the matter. Others may have had personal reservations but significantly, none of these people campaigned for a No vote, given their parties’ official support for a Yes vote.
Division among religious figures
The Catholic Church has come on hard times in Ireland. The church used to play a dominant role in shaping sexual and social mores in the country. As pungently described by Fr. Patrick Hederman (full disclosure: he once taught English to one of this post’s authors)
Ireland is a prime example of what the church is facing, because they made this island into a concentration camp where they could control everything. And the control was really all about sex. They told you if you masturbated, it meant you were impure and had allowed the devil to work on you. Generations of people were crucified with guilt complexes.
However scandals about sexual abuse — and the willingness of the church hierarchy to cover it up — have precipitated a calamitous decline in the social authority of the church over the last decade. This, together with greater internal opposition to the official position than in the past, meant that the church was in a much weaker position than in previous referendums. While church leaders did come out against gay marriage, and many priests advocated a No vote from the altar, they left most of the organization of opposition to a relatively small network of religious conservatives and their allies. It was also likely important that some religious figures, including widely admired anti-poverty campaigners such as “Sister Stan” Kennedy and the Rev. Peter McVerry, came out in favor of gay marriage – these individuals retain much of the moral influence that the church hierarchy has lost. Equally, the willingness of other high-profile figures to endorse gay marriage — including a former president of Ireland, Mary McAleese (whose son is gay), country music star Daniel O’Donnell and former broadcaster Gay Byrne — made it harder for No campaigners to portray themselves as defenders of mainstream Irish values.
It will be interesting to see how the Catholic church responds to the referendum. Archbishop Diarmuid Martin has acknowledged on Irish television that this is (as Varadkar has described it) a social revolution, and that the church faces an enormous challenge in figuring out how to speak to young people. Eamon Martin, Archbishop of Armagh and Primate of Ireland, hinted during the campaign that the Catholic church could consider whether it would continue to support civil marriage through church weddings, if the referendum passed. However, the Catholic church has already lost the allegiance of large sections of Irish youth anyway, not least because of its traditional teachings on sexuality and marriage.
Strong campaigning by the Yes side
Full analysis of the campaign will have to wait for all the data to come in. The Yes campaign – which was highly active and run by enthusiastic supporters – brought together a wide range of civil society organizations into a broad-based coalition that was immensely successful in getting voters to the polls, and in energizing young Irish voters. It seems plausible that the very many personal stories shared in public and through social media helped sway the debate toward Yes, including moving personal testimony by well-known individuals such as journalists Una Mullally and Ursula Halligan.
A research article by LaCour and Green, published in Science claimed that personal stories and personal connections helped to change people’s minds and make them more likely to support same-sex marriage. Although campaigners may already have been using similar tactics, the Irish Times argues that this research “provided a template” for campaigners to use one-to-one contact and first person accounts to reach out to more conservative voters. As Kieran Healy has noted, it turns out that the LaCour and Green article was based on faked data. Happily for the Yes campaigners, even if their strategy was based, at least in part, on bad science, either the effect that Green and LaCour argued for was really present, or support for marriage equality was sufficiently strong that it didn’t really matter either way.