From Aleteia, some analysis from Michael Cook:
As an institution, marriage has been on the skids in Ireland for decades and Friday’s result was a natural result. It wasn’t the gays who trashed marriage; it was the straights.
Consider the four essential features of traditional marriage: permanence, monogamy, procreation and sexual complementarity.
Permanence: Ireland amended its constitution in 1995 to legalise divorce (with a 62 percent voter turnout), copying what other jurisdictions had done decades before. So “till death do us part” was removed from the marriage 20 years ago.
Monogamy: Between 1996 and 2011, there was an increase of nearly 550 per cent in remarriages after a divorce or an annulment, from 6,641 to 42,960. As in the United States, the United Kingdom or Australia, Ireland embarked on a modest program of serial polygamy.
Procreation: Ireland’s birth rate is high, compared to the rest of Europe, but it has been declining steadily. In the 1960s, the birth rate was about 4 children per woman. Now it is hovering a bit below replacement level. Children are less and less a part of marriage.
Given these radical changes in the way men and women commit themselves to each other in marriage, the common understanding in Ireland, as in most other Western countries, is so altered that the grandparents of young voters would hardly recognize it. It is no longer marriage, but marriage-lite. Of course, this is not a problem in the eyes of gays and lesbians. In fact, it is precisely the possibility of divorce, the tolerance of extra-marital relationships, and the optional character of children which makes marriage-lite attractive. The traditional version would hardly suit them. It is only logical that the fourth feature of marriage, sexual complementarity, now seems unnecessary to so many people.