The key to winning the marriage equality argument is to separate the idea of who is married in the eyes of the state from who is married in the eyes of God.
The legal act of marriage is a contract, and the laws of the state regulate who is allowed to enter into contracts. Do those who oppose gay marriage oppose gays being able to enter into any legal contracts? Do they oppose letting gays buy houses and own businesses? Even the most rabid wrongwingers have a hard time justifying that--look at what happened when they tried to go that far in Virginia.
The "sacrament" of marriage is a religious act, and different denominations have different rules about who can be married in their church. Many Protestant churches do not even use sacramental language about marriage--they do not consider marriage a sacrament in the same way that Anglicans/Episcopalians and Roman Catholics and some Orthodox religions do.
The key to winning the marriage equality argument is to separate the idea of who is married in the eyes of the state from who is married in the eyes of God.
These two concepts are not the same thing. People who are opposed to marriage equality have gotten a lot of mileage out of claiming they are the same thing. The US claims to have separation of church and state, but marriage is one of those areas where the lines have been very blurred. Anyone who gets a "church" wedding goes before a solemnizer (priest, rabbi, minister, imam, etc.) who when s/he signs the marriage license, is acting as an agent of the state. The European model, which completely separates legal marriage from church marriage, is very wise, and I believe the US should move toward this model, but until we get there, we will continue to have widespread confusion equating legal marriage with religious marriage.
I don't want to single out Roman Catholics, since there are a lot of conservatives refusing to marry gays, but it is easiest to illustrate this point using that denomination. Let's consider Pat Buchanan and William Buckley. Their religion interprets the bible as saying that divorced people should not be allowed to marry. And Roman Catholic priests will not marry divorced people under most circumstances.
First, imagine an opposite sex couple, both of whom were previously married in the Roman Catholic church, both of whom are divorced (without an official annulment). They cannot get married in most Roman Catholic churches. But if they take their marriage license to a Justice of the Peace, and get married there, even Pat and Bill will consider that couple to be legally married, even though it was against the doctrine of their own denomination and their own denomination refused to marry them.
And if that same opposite sex couple takes their marriage license to the UCC, or some other denomination with a different view of divorce, and get married there, Pat and Bill will consider that couple to be legally married, even though it was against the doctrine of their own denomination and their own denomination refused to marry them.
Why should gays who go to a Justice of the Peace or to the UCC church to be married be considered any differently?
Gay marriage is legal in Massachusetts, as most of you know. But Roman Catholic priests and other conservatives are not being forced to marry gay people just because the state says it's legal, just as Roman Catholic priests cannot be forced to marry divorced people just because the state says its legal. Any priest or minister or other solemnizer can refuse to marry any couple for any reason, or without giving a reason. But if that same sex couple takes their marriage license to the Unitarian Minister and has a wedding there, why is that the business of more the conservative denominations who refused to bless the couple?
Do the Roman Catholics want the UCC telling them who they can marry? Then why do they want to tell the UCC who they can marry?
So. The state decides who can enter into the complicated series of contractual obligations that constitute secular legal marriage. Each religious denomination decides which couples can receive a religious blessing from that denomination. The secular and the religious aspect of marriage are already separate.
Eventually even the wingers will have to accept this separation between church and state. The beauty of this concept is that they can still be as bigoted as they want within their own church walls. They can quote Leviticus to their hearts' content and claim their God hates gays and doesn't want them to marry. But they can't tell other denominations what to do, and they can't tell the state what to do. We avoid the Equal Protection arguments altogether.
Polls show consistently higher support for "civil unions" than for "gay marriage" because many people are stuck on the idea that the word "marriage" conveys a religious concept. Marriage equality proponents should be encouraged by this instead of complaining that it is a halfway measure. Civil unions may be a necessary intermediate step until people get it through their heads that
- secular marriage is equally valid as religious marriage;
- secular marriage has an equal right to the use of the word "marriage";
- it is the "state" and not the church(es) that determines who can enter into the legal contract(s) of secular marriage;
- the church has no authority to tell the state who can enter into the contract of secular marriage;
- different churches already make different decisions about which marriages can be blessed, and will continue to do so;
- church A cannot impose its doctrine and interpretation of scripture on church B and thereby insist that church B refrain from blessing certain marriages;
- so long as we still have a First Amendment (but look out for Chief Justice Scalia, Associate Justice Gonzales and other activist conservative judges in the pipeline), no church, no matter how powerful, no matter how large a majority in the population, can constitutionally impose its doctrine and interpretation of scripture on the state.
That said, I am going to surprise everyone by saying that I (and Lakoff) understand exactly what wingers mean when they say that gay marriage threatens the institution of marriage. They are absolutely right that patriarchal marriage as they understand it, with one man the head of the household, king of his castle, master of all he surveys, with absolute control over his wife and children, is threatened by a marriage between two men. That's why they always ask inane questions like: "who's the bride and who's the groom?" What they mean is, who has the power and who is the subservient one, because that is their only model of marriage. And a marriage between two women is equally confusing to them--a marriage in which no man is even necessary is too potent a symbol of how ineffectual and superfluous they are beginning to feel in other realms of this pluralistic society.
In fact, any progressive marriage where the two partners treat each other as equals and don't have a "head of household" or implied sense of one owning one another or master/slave power struggles with one another threatens the future of patriarchal marriage.
Those poor scared white guys and the women who depend on them for their economic and psychological security--sometimes I almost feel sorry for them. Marriage equality is one more nail in the coffin of their antebellum lifestyle; and the "war" they are losing this time is the war to maintain the historically exclusive advantages of white men--power, rights and privileges that their grandfathers and great-grandfathers didn't have to share with women, blacks or gays.