Thank goodness for my pseudonym: If you're going to make me commit, then here's my "feeling" on the matter. I think that homosexuality is not a basis to restrict marriage. Why does it make a difference as to the sexual orientation or gender of those who get married? It can't be about procreation (there's not obligation to do so when married and may married couples can't reproduce). It can't be about religious beliefs, because that can't be a basis for the government to deny or permit.
No, marriage is about stability. We believe that when people are married, it helps stabilize our world. It fosters stability in property, in family, and in social relations.
Those against gay marriage can't really espouse a reason why the government shouldn't sanction it without bringing in religious beliefs. They can speak about "preserving our heritage" all they want, but gay marriage doesn't disrupt hetero marriage or its traditions - it only adds another group to what we have now (with that current group not being altogether successful at it in any rate).
Those opposing the issue don't want more members into the club because then they can't look down on those on the outside. They become too similar - and nothing like familiarity to breed contempt. As long as they can exclude the homos, the heteros can remain superior. Just like with the race laws that are slowly dying, so too will the anti-homosexual laws. The same exact arguments are used; which boil down to: "it doesn't seem right." And by the way, I don't know that I'd apply the "Rational Basis" test to this issue, but that's another post.
I would restrict the right to marriage to some though. Murderers, child-molesters, and rapists come to mind. If marriage is about liberty (so says Warren) then take some more liberty away from those who don't deserve it.
Don't punish a group of individuals that have produced some of the most breath-taking art and literature (not to mention inventions and ideas) the world has ever known just because they reject your idea of sexuality. They have every right to every other liberty we bestow upon mankind (we even so graciously allow them to create life and adopt) except the right to express their commitment to one another in a way that is legally recognized.
Preserving anachronistic ideals is not the basis for forming government policy. Otherwise, bring back slavery, by all means. I have some projects at home I'm too busy for.