From Jennifer Thieme at the Ruth Institute:
A red herring is something that distracts people from the issue at hand. It allows people who are otherwise thoughtful and intelligent to not think about another topic too deeply. Libertarians often make claim to “get the government out of marriage,” but this ends up serving as a distraction from the real policy issue at hand. There are a several reasons I believe it’s a red herring, or at least an idea that people haven’t thought through too well.
First, I do not think it is realistic to believe the government will actually get out of marriage, especially once the definition of marriage becomes sexless (genderless) as a widespread policy. Sexless marriage as a policy is what must happen in order to allow gay couples to marry. It wasn’t fair that only straight women could be brides, and only straight men could be grooms. So now no woman gets to be a bride, and no man gets to be a groom in same sex marriage states. The state will not likely give up the increased power it gets over individuals, children, and the church as this change gains traction.
Second, how would we accomplish getting the government out of marriage? Marriage is part of so many social policies, from tax law, to food stamps, Medicare, Social Security… the list goes on and on. Extracting the concept of marriage from all of these policies, at the federal level, at the state level, and perhaps even at the local level seems extremely unrealistic to me.