Mark Vernon, who is in a British civil partnership (CP) himself, argues for keeping CPs gay-only:
[N]ow that we have an institution that affords us the same legal protections as marriage, my sense is that we should allow CPs time to take shape as a gay institution – to toy with the historical and cultural specificities faced by lesbian and gay relationships, and not faced by straight ones… It takes time for institutions to grow the wisdom, as it were, that is good for people. What clearly doesn't help is the over-use of the blunt instrument of equality. It becomes the hammer that sees every issue as a nail.
It's a language that has, in recent times, served gay people well. But now that we have an institution that affords us the same legal protections as marriage, my sense is that we should allow CPs time to take shape as a gay institution – to toy with the historical and cultural specificities faced by lesbian and gay relationships, and not faced by straight ones.
I do not doubt that gay marriages and lesbian civil marriages have very different dynamics than many civil straight marriages. But the range of experience within straight marriages – from open to strictly monogamous, from arranged marriages to consecutive ones, from working mothers and stay-at-home fathers to classic patriarchy – seems to me to make the difference between all these and gay marriage much less impressive. A lesbian couple with kids, for example, seems to me to have more in common with a straight couple with kids, than with a post-boomer, career-driven straight couple with no intention of having children or a male-male partnership based on mutual support, emotional stability and a dog.
And my real point here is that I think we should try not to balkanize society excessively.
If we can bring more people into the same civil institution, we reduce the divisions of identity politics, advance the notion of citizenship and humanity that trumps sexual orientation, and bring gay people into their own families and traditions. This is far preferable in my view to carving out a separate and equal ghettoized institution where gays are required to sequester themselves from their married heterosexual siblings and peer, where their gayness and not their humanity is the most salient fact about them.
Which helps reinforce one conservative case for marriage equality: it is opposed to identity politics. And it is a tragedy that so many conservatives who would otherwise oppose identity politics cannot see this.