Solid Lifters
Today, it's unfathomable to think how people then could support or allow slavery. Today, it's a huge embarrassment and has stained our nations history. To some degree, so will this issue. But how long will it take?
It's a good question. At least it's hopeful that the number of countries addressing this injustice is growing rather than decreasing. The injustice is becoming clearer, and I predict it will take at most one more generation before the U.S. will recognise gay marriage.
Also, I see Brian's point on one person's rights limiting others, but he has already shown a willingness to overcome the problem he himself sees in favor of the happiness of millions. I think, however, that it doesn't need his generosity, but can also be more legally addressed.
The rights of the individual as protected by the constitution are such that in what the government provides, all men should be equal. This supercedes the laws of different religions. Someone who subscribes to, say, Catholicism, does so voluntarily and then can go on to decide for himself whether or not he will be a practicing homosexual or whether or not he thinks it's a sin to use a condom.
However, the rights and priviliges afforded to a married couple are rights that apply to all citizens. Therefore, denying people that right because of their sexual preference is a grave legal aberration.
Some arguments go that marriage is the cornerstone of society and to 'degrade' it into a union between people of the same sex are nonsense. In a state that has 'manually' instated a same-sex marriage ban, men and women are allowed to marry, even if they are not going to have children, are not in love, or whatever. The benefit of this situation to society is that two people committing themselves to each other makes for a more stable society, because these people care for each other and can help each other out. Whether these are friends, strangers who see a financial benefit, old roommates, or people truly in love, it doesn't (and shouldn't) matter for the law. For that reason, however, there is also no reason not to allow two people of the same sex to marry, whether they are homosexual or not.
Also, in this married state, all the people above are allowed to adopt a child. A single mother is allowed to raise her own child. Now, if two single mothers were to join forces and raise their children together, they would certainly be better off, because they would have each other as backup. It's more cost and time efficient, and can handle more setbacks. Now replace the mothers with fathers, the situation doesn't change. Same-sex marriage should therefore be legal on principle, in complete disregard of the opinion of homosexuality. But adding homosexuality to this mix does not change matters. Whether or not two men or two women (or, for that matter, a homosexual man and a homosexual woman) who marry and raise children together, it does not matter.
You can actually see that judges are starting to realise the injustice. Recently, I read the story of someone on another board who was fighting a custody case with a bitter ex-wife. The judge basically said that he recognised that the father and his boyfriend would be a more stable environment for the children, but that the boyfriend wouldn't be allowed to stay in the house overnight, because the children would get bad ideas from this. The number of things wrong, both scientifically and legally, with this latter comment, is so large and obvious, that the injustice of the ban on same-sex marriage will soon be redressed.