Eugene Volokh has interesting thoughts the slippery slope in this case. A sample:
[I]f we take the New Jersey Supreme Court at its word, it sounds like in New Jersey antidiscrimination laws, domestic partnership laws, and hate crime laws did indeed help bring about same-sex civil unions, just as they did in Vermont ...and, as to same-sex marriage, in Massachusetts.
One can condemn this slippery-slope effect, or praise it. (I support same-sex marriages and civil unions as a policy matter..., but I don’t think that state courts should mandate them as a constitutional matter.) But I think that one can’t dismiss the possibility that slippery slope effects, good or bad, are indeed present here, and can be present in similar contexts. And this is so even when, as a purely logical matter, the initial steps (employment discrimination bans, domestic partnership laws, hate crimes laws, and the like) are eminently distinguishable from the final step (same-sex civil unions).
Read the whole thing. Hat tip:Stanley Kurtz.