Some people, such as Mike Huckabee, have proposes a Constitutional amendment banning same sex marriage. This strikes me as a bad idea.
My main opposition to this idea is not based on my views of same sex marriage. It is, rather, based on my view of the function of the Constitution and other bodies of law. This, in turn, shapes my view on what sort of laws should be a matter for the Constitution and what should be a matter for “lesser” laws.
In various debates with people on this matter, many bring up the argument that since same sex marriage is immoral it follows that it should be banned by the Constitution. My standard reply is that the function of the Constitution is not to ban immoral actions. This is shown, in part, by the contents of the Constitution itself. It is primarily a document that enumerates rights and the nature of the state. As such, a ban on same sex marriage does not seem to fit the document.
In response, some people try to counter by saying that the Constitution exists to protect us and since same sex marriage is a great evil, it should be banned at that level.
In response, think about things like murder, rape, and theft. None of these are outlawed by the Constitution. It is not that these deeds are not important or not evil. They are not covered by the Constitution because such matters are handled more appropriately by other types of law. Unless we are wiling to accept that banning same sex marriage is vastly more important than protecting people from murder and is on par with fundamental rights, then there seems to be no reason to make it part of the Constitution.
If same sex marriage is actually a great evil, on par with murder and theft, then it should be outlawed in the same manner that these are outlawed. It does, however, have no place in the Constitution.