I am not sure I agree with Colin James that this might prove the high-water mark of social liberalism in New Zealand. This country, perhaps more than any other, has refused to turn its face away from the bright lights of Enlightenment civilization. We remain, one might claim, the "City on the Hill" for civilized people everywhere. While Kiwis are sometimes suspicious of the motivations driving social change, they rarely actively oppose it in any numbers - and even more rarely try and wind it back.
This is a good thing. With countries like the United States beginning to reconnect religion and politics, our little secular oasis could quite possibly become a destination of choice for coming generations of intellectual talent from around the world. It's an intriguing prospect. Imagine New Zealand as a sort of refuge for talented people in all walks of life -- a place away from the gale of war, of fundamentalism, of hate and of crisis sweeping the rest of the world -- and be very glad we are so far away from everywhere.
I'm confident that Civil Unions will pass into law, and that in a couple of years nobody will remember what on earth the fuss was about.
The challenge facing liberals (who are both left- and right-wing) is to be much better at explaining the moral reasoning behind our positions. In the absence of strong moral claims about why what we support is right, we leave all the running on "morality" to the conservatives, and that is not ground any of us should be considering giving up.
As Martin Luther King said, "discrimination anywhere is discrimination everywhere" - and we should be able to celebrate soon enough the end of one aspect of legal discrimination against a minority in our country. Cheers to that.