William Butler Yeats, who belonged to a long tradition of Irish nationalists who were Protestant, foresaw the consequences: “If you show that this country, Southern Ireland, is going to be governed by Catholic ideas and by Catholic ideas alone, you will never get the North. You will create an impassable barrier between South and North.” And so it was.

Friday’s vote is the culmination of events that have effectively ended that tradition. The Catholic Church’s “special position” was dropped from the Constitution nearly 40 years ago. Contraception has been legal since 1980; divorce, since 1996. The books once declared obscene are no longer banned. Abortion remains illegal, but the laws have loosened; the procedure is now legal for women facing risk of death or suicide. And even the Church itself is changing: Some Catholic priests announced they would be voting “yes” in the referendum.

In fact, it is no longer an exaggeration to call Irish laws freer from religion’s sway than those in Northern Ireland, which is the only part of the U.K. where same-sex marriage remains illegal. The North’s leading nationalist (and largely Catholic) political party, Sinn Fein, pushed for legalization in 2013, but failed to overcome opposition from the two largest Protestant parties. The debate there has mirrored the one in the U.S., where evangelical Protestants form the bulk of the opposition to same-sex marriage. And as in the U.S., it may be the courts that force the government to recognize it.