Near the end of his anti-gay marriage article in today’s Age, Ted Lapkin does get to some substantive reasons why he thinks gay marriage is a bad idea. But much of the article is devoted to the slippery slope argument that once we have gay marriage we will slide into things we really don’t like, such as legal recognition of polygamy and decriminalising incest.
I don’t disagree with Lapkin that issues can develop their own logics, and that one change can make another change more likely. I think we are now nearing the base of a moderately slippery slope on gay issues. Once the state gave up on the idea of actively persecuting gay people for acting on their sexual desires, it became harder and harder to defend all the other ways in which the law disadvantaged them.
Lapkin himself says that everyone, gay or straight, is entitled to identical protections from the law – something that few conservative defenders of the family would have said until quite recently. Once you are sliding on the slippery slope, it can be hard to stop. The last conservative stand on gay issues at the Marriage Act is no more likely to succeed in the end than any of the other battles along the way.
The question then is not whether slippery slopes exist, but whether you can slide from one slope to another in any kind of deterministic fashion (“The floodgates will inevitably open to a further slide down the slippery slope of social disintegration”.)