Two weeks ago, relatively quietly, the world changed in DC. On Wednesday March 3 the government of the District of Columbia began issuing marriage licenses to same-sex couples. The video below is of the first same-sex wedding in DC, a week later. [youtube=http://www.youtube.com/watch?v=dSKcq5U_MLs]
DC has joined five states in allowing same-sex couples to wed: New Hampshire, Iowa, Massachusetts, Vermont and Connecticut.
This is the civil rights issue of our time, but the change it brings is barely noticeable. It's almost amazing how completely non-disruptive it is, even to those most opposed to it. As despicable as it was segregation was a way of life, and giving up a way of life and the set of traditions and beliefs around it is very difficult for many people.
Those opposed to gay marriage however are defending a way of life only in their minds. As the five existing states in America have shown, nothing happens when you allow same-sex marriage other than people of the same sex getting married. Heterosexual marriage continues as normal. Even for those most opposed daily life continues exactly as it did before. They are required to give up no traditions at all and it can only be a matter of time before most realize that the only belief they are giving up was a mistaken one: that gay marriage in some way threatened heterosexual marriage.
I feel fairly confident that most of those casually opposed to gay marriage will get over it pretty quickly. It will be hard to continue to make claims about the destruction of the institution of marriage when the institution continues as before, if not stronger. It's harder to be scared of something that happens routinely around you without any negative repercussions. And as the states and jurisdictions which allow gay marriage slowly increase in America, it will become harder and harder to make a credible argument against it anywhere.
6 countries currently allow gay marriage: Belgium, Canada, Netherlands, Norway, South Africa, Spain and Sweden. I suspect the institution of marriage is getting along just fine there as well.