As I said in my recent post "Gender, Gay Marriage and Galileo" -- we have to get past the mental obstacle that marriage is for specifed categories of people. We have to stop tying it to notions of gender or chromosomes or sexual orientation. The noisy political arguments always develop around how to define these categories....which is how the religious right wind up wanting to deny marriage rights to the "gay" category. It's also how LGBT people wind up arguing whether it should be called "gay marriage" or "same-gender marriage."
Instead, we could be talking about "universal marriage." This is a far more human, and user-friendly idea, with a clear precedent in American history.
Marriage should be about PERSONS, not categories. Human personhood is a universal thing. Marriage seems to be a universally human thing, with two people bonding together for whatever purpose a society wishes. Marriages work universally even when children don't happen -- for instance, to provide economic security and to alleviate loneliness in old age. So the idea of personhood should be the basis for marriage between two human beings if they wish to live in that state, regardless of what their gender or sexual orientation is, and regardless of whether they plan to have children or not, or even whether they're capable of having children or not. So we could call it "universal marriage."
Historically, marriage was far from universal, and often limited to certain categories of people. A couple of years ago, I wrote a lengthy piece on the history of marriage for Gay & Lesbian Review. Marriage history is full of surprises, and the religious right often lie in their teeth when they talk about it.
For many centuries the Roman Catholic Church controlled everything in Europe, so you could only marry in a Catholic church in front of a priest, i.e. married couples had to be Catholics. Then along came the Protestant reformists, and they told the Catholic Church to go screw itself. The Protestants then pioneered the concept of "civil marriage" (i.e. you could marry in front of a representative of local civil government). How ironic that some of the same religions who say today that "all marriage is sacred and heterosexual" were once the religions who pioneered the right to civil marriage -- an idea that was revolutionary and rabble-rousing in its time!
So marriage is best defined by the purely human, not by categories of persons. Animals are not humans. So a concept of human marriage gets around the religious right's panicky insistence that "if gay marriage is legalized, people can marry their pets."
When the United States launched in the 1700s, access to marriage faced a problem because most states were controlled by a single state religion. New England States were Congregational, while Virginia and Maryland were Anglican, for example. This created some legal cans of worms. You could only have a valid marriage if you were married in the church in your home state...which could have meant that your marriage was not recognized in another state. Marriage was one of the legalities left to the states to regulate...and it was also one of the reasons why our founders had to get rid of all the state religions and invent the idea of "full faith and credit" so that certain legalities would be legal in all states.
The concept of "universality" already has an interesting precedent in U.S. history -- namely with the right to vote. It was -- and still is -- called "universal suffrage."
Under the original state constitutions of the 13 former colonies, voting rights were very narrowly granted -- to free white male Christian property-owners. Little by little, through amendments to state constitutions and the U.S. Constitution, the right to vote was broadened towards what came to be called "universal manhood suffrage" -- meaning that a free man could vote whether he owned property or not.
Eventually Catholics and Jews and members of other religions were allowed to vote, as were former slaves, and finally women. By then, people talked about "universal suffrage." Now and then, there have still been attempts to disenfranchise whole groups of voters. For example, in the 1930s, during the Great Depression, there was a big political flurry over whether to deny the vote to all the millions of people who were unemployed or homeless.
Today, technically, we do have "universal suffrage." But in practice it isn't quite "universal." There have been flurries over whether people who are illiterate can vote. Today we still deny the vote to minors, and to 5 million people who are convicted of felonies. Disenfranchised felons include many black men...which is why the criminal justice system's habit of punishing blacks more severely than whites has become a huge voting issue. This tragic problem of the black male vote is something that must be fixed, and soon.
But at least we as a nation have committed to the ideal of "universal suffrage." Why can't we commit to the ideal of "universal marriage"?