For the most part, I have been pretty much a supporter of same-sex marriage, at least from the standpoint of government. I voted no on a defense of marriage proposition that was on the ballot in Arizona a few years ago. First, with respect to marriages in general, the government doesn't require marriages to pass moral tests in order to give marriage licenses. For example, if someone began their relationship with an extramarital affair, has then finalized their divorce or divorces, the state doesn't ask questions, it grants the license. Given this, it seems hypocritical for governments to , for example, give a marriage license to Newt Gingrich but not to George Takei.
Second, there seem to be cases where SSM seems pretty reasonable. For example, if someone has been in a same-sex relationship for many years, but their family has disowned them for being gay, and then the person goes to the hospital and end-of-life decisions have to be made, the lifetime partner, not the family that disowned the gay person, seems to me the right person to make those decisions.
But there are other issues that bother me about it, and these have to do with people who conscientiously believe that same sex relationships can't be real marriages. For example, I don't think people in the business of wedding services, such as florists, bakers, and photographers, should be exposed to discrimination lawsuits because they don't want to service same-sex weddings. I don't think Christian adoption agencies should be forced to accept applicants from same-sex couples if it is against their principles. I don't think Christian college philosophy departments should have a "discriminator" tag put on them by the American Philosophical Association because they have codes of conduct that require faculty hires to abide by a code of sexual conduct that requires them to restrict sex to heterosexual marriages. (And please note that a gay person could fulfill those requirements by simply being celibate). I don't think businesses like Chick-Fil-A and executives like Brandon Eich should be punished economically because they don't believe in same-sex marriage. If this is what supporters of same-sex marriage want, if this is where it is going to be pushed, then I am inclined to say "let me off the boat."
That is why I would prefer to see governments give out civil union licenses and only civil union licenses to everyone who goes downtown for a license. That would, I think, leave individuals and "churches" (and this would include secular groups) to determine by their own lights what is a real marriage and what is not. I don't know if this is workable, but something along these lines is the only acceptable solution. Whatever solution is adopted should be fair to both gay people and critics of homosexuality.
It's time to stop looking to government to determine what is right and wrong. I wouldn't quite say "You can't legislate morality," but I will say that there are large areas of morality that you can't legislate.
This essay, Freedom to Marry, Freedom to Dissent, Why We Must Have Both, reflects the position I have been defending here.