From a U.S. perspective, the debate over gay marriages and their right to do so have been focused on their civil rights as citizens, but I think their very debate is erroneous because marriage is not a universal right. It's closely regulated here. In many states you can't marry family relatives and in all states only one spouse is recognized and is, as a matter of fact, unlawful to have more than one spouse. Some states even deny marriage to people with STD's, so it's not like gays or lesbians are the only ones who are denied of marrying somebody of their choosing. Now, I'm not really comparing gays to any of these groups, but rather pointing out the tight regulations on marriage because they are made into law for good reason. The state has a vested interest in a marriage between a man and a woman because such marriages will propagate the state.
When the state grants marriage, they're entering into a costly venture. In the U.S., the spouse of the deceased social security recipient will continue to receive their benefit for instance. Married couples can get certain tax benefits. Health insurance can be shared at a cheaper rate. So, really - in many ways - a married couple receives a subsidy from the state. In return for that subsidy, a married couple increases the tax payer base (and loves doing it). They ensure a maintenance of demography for the state. Of course, you could argue that sterile couples also marry and elderly and so on, but those cases are rare and are probably not cost efficient for the state to determine if they're a viable couple for propagation.
A homosexual couple obviously serves no such benefit to the state. Unless they do something else for the state, they are essentially trying to achieve these subsidies without providing benefit. It could be argued that lesbian couples at least have the capacity to propagate, but the act of marriage itself does not guarantee or even speculate that result.
Other than these "marriage benefits" stated, the U.S. does not regulate any other obvious attribute of marriage. Gay couples are free to own a home together, a car, share their wealth in whatever ways suit them. They can live together, love each other and build a home. Gay couples are, however, asking the State to recognize a marriage between two men or two women simply because they love each other. States understand that such a recognition could result in any such marriage based on the same criteria. Let your imagination roll.....
That's my Thecular view!
