Or at best, they are moderate anarchists.
talks about the need to "protect" the sanctity of marriage, his plea is a giant non sequitur because he does not explain what, precisely, he is protecting marriage against.
It's easy to understand what you're protecting marriage against if you know what marriage is for. (HINT: It's not for two couples to express their love for each other).
Marriage is a sociatal contract that ensures a society remains intact generation after generation. It protects children, and ensures that they will be raised by a stable family system. Like the human body is made up of cells, so are human societies made up of families. Marriage is the DNA of humanity. Tampering with it on a large scale is suicidally reckless.
Why? Because marriage is society's way of protecting itself from anarchy. It is NOT a public declaration of love, it's a declaration of responsibility. Two gay people, no matter how long they are together, will never procreate. They will never be as valuable to society as a married couple.
Is this fair? What about couples without kids? How are they different from gay couples? Simple. Even straight couples that say 'they'll never have kids' often do, which is why we still cover them under the umbrella of marriage. A small percentage never will, but there's no way to know that from a the inception of a straight marriage.
A gay marriage, however, is of no more consequence to the world that an abstinant hetero couple who are going steady. Certainly they can be in love, but that's an individual issue, and their love does not require our recognition, tax dollars, or approval.
And that's what gay marriage is all about. Recognition, money, and approval.
There are unintended consequences of destroying a 'one man one woman' marriage system. It opens the legal door to polygamy, polyandry, and anything else that 'freedom of association' could dream up.
If you think that there are people in America that would not marry their housepets, think again.
Destroying the sanctity of marriage will destroy any culture, no matter how powerful it weapons, or how rich its economy, or how enlightened its people. No tribe of humans has risen out of hunter / gatherer status without it. To think we can transcend it now because we're somehow more advanced as a species is to ignore human nature at its core.
You're arguing that in cases where it is a confirmed medical fact that a married couple can never have children, that such a marriage should be desolved by the state. You're full of it.
Sorry, but there are cases in which it is absolutely, positively, 100% certain that a given couple will NEVER reproduce -- and it only takes one such case to defeat this argument.