Many of my friends and colleagues in other parts of the world are having a really hard time wrapping their head around the continued controversy in the U.S. regarding "gay marriage." And by that, I mean, "marriage" open to same sex couples, not some new magical thing that has never existed before. Such marriages are so accepted in many other countries today, that these friends think it is simply a requisite part of being a modern nation, and see current legal controversies in the U.S. as evidence that we are morally stuck in the dark ages. Maybe we are morally stuck in the dark ages, but I don't think this controversy is as straightforward as that makes it sound. I am not advocating either position below, just trying to explain the depth of the controversy.
The issue is not, fundamentally, about hating homosexuals. Most Americans have reached the point where they don't much care what other people do in their bedrooms. Yes, there are people who think it is indecent for homosexuals to "flaunt" their relationships in public, but much of the U.S. is conservative enough that they find any public displays of affection distasteful. The core disagreement regarding gay marriage is about the type of situation that marriage is analogous to.
What do the progressives think?
Those who are more progressive in their thinking see marriage as something much like any of other legal agreement. Selling a house is a good example of a contract that requires extensive legal work and has significant consequences. Let's say a single person has a parent who is helping them buy a house. Is there a reason for me not to sell my house to a son being helped by his father (two men)? No. Is there a reason for me not to sell my house to a daughter being helped by her mother (two women)? No. Ditto for selling it to a same-sex couple. Why should I care if it is two men or two women signing the dotted line to enter into a legal agreement? Once they co-sign for the mortgage, and co-sign for the house, there lives are legally intertwined in some pretty complicated ways that are hard, but not impossible to undo. It is a pretty significant commitment. If we were going to allow that, why would we stop them from signing on the dotted line to enter into the legal entanglement we call marriage? The only reasonable answer, that these people can come up with, is because the opponents to same sex marriage are bigots.
What do the non-progressive thinks?
Those who are against same sex marriage think marriage is less like a legal contract and more like a baptism. Sure, lots of religions perform baptisms, but not all religions recognize other religion's baptisms. A Catholic might not recognize a Mormon baptism or vice versa. Don't get me wrong, a Mormon does not deny that a Catholic went through a Catholic Baptism Ceremony, but that doesn't mean they are recognized as baptized in the Mormon faith. Among other things, so far as I understand it, Mormon baptism (similar to several other Christian sects) requires a conscious choice to participate, and so it would not be relevant if you were "baptized" as an infant. Though most Christian sects play nice with each other these days, one can easily imagine that members of some Christian sects would be unwilling to take part in a more unusual baptism ceremony, for example one involving speaking in tongues. One can even imagine (because they exists) other religions with baptism ceremonies that most Christians would not want to take any part in because they would see participation as sacrilegious. Some Christians would see it as their religious duty to try to stop others from taking part in such ceremonies, others would simply not want to take part, and none would want to be legally compelled to deal with someone else differently simply because that other person took part in such a ceremony: That would logically entail forcing them to recognize such baptisms as legitimate.
No, this analogy is not a stretch. I have been to more than one marriage ceremony where it was asserted that the marriage being created was, "A metaphor for Jesus's relationship with the Church." They were not saying that Jesus's relationship to the Church was metaphorical, that was the real thing, the enduring thing. The marriage was a metaphor, it was fundamentally a religious ceremony with religious connotations and creating religious obligations. At one of the ceremonies, at least, the woman who made the cake was a member of the Church where the ceremony took place, who had known the bride since birth. For her, making the cake was taking part in the ceremony. It was the embodiment of her joy for the couple, her well wishes for them, and her endorsement of their union as a fitting simulacrum of Jesus's relationship to the Church. For this woman, the act of making the wedding cake was not at all like making standard cakes to be sold to anyone who came in the door, or making a cake to bring to a potluck barbecue, it was, first and foremost, a symbolic and religious act; it was akin to custom-creating symbolic items for a baptismal ceremony.
So what now?
I'm not saying that either point of view represented here is right or wrong, I'm just trying to explain the odd nature of this debate in the U.S., which might not be apparent to those outside. Many who think of marriage as akin to a baptism don't feel any need to stop same-sex couples from entering into legal contracts, even contracts with all the legal implications currently associated with marriage. But the word "marriage" for these people has primarily a religious implication, and they are not going to be convinced to view marriage as non-religious anytime soon.
I know many other countries have simply secularized marriage, and that might well happen in the U.S. However, in our context, both our legal context and our cultural context, the more logical solution, I would argue, is to separate marriage from the state altogether. We should have civil unions with the full legal implications currently associated with marriage, and we should have marriage ceremonies associated with whatever religion the participants are part of. The federal government, in this arrangement would have two clear obligations based on the constitution: 1) Ensure that consenting adults, regardless of sex, can enter into legal contracts, and see to it that such contracts are enforced without bias. 2) Ensure that people can have their religious marriage ceremonies in whatever way conforms to their deeply held beliefs.