Fashioning "a decent society" is certainly a matter of moral perspective, and one we probably agree on morality-wise. I don't want my kids hanging out in Hugh Hefner's neighborhood because kids are not ready for adult behavior or the consequences thereof. That's why parents keep an eye on their kids, to help them know what to do when they are ready to judge for themselves.
On the other hand, I don't feel I should have any say on what Hugh does in his home, or what my kids do after they leave my home. Obviously, you disagree and think it's important to regulate what people do in and outside of their homes insofar as the legal status of their spouse is concerned. Never mind that the only difference in the legal status is who can be a current WIFE, not current floozy, so your 'upholding decency' argument really holds no water. What you want is to uphold your version of morality in LAW, never mind the actual negative social consequences of that illegality or its inability to effect any positive change towards your perception of good. You prefer the spirit of the law to its reality. And what you consider a factor in 'dissolution' has been a part of many stable societies for hundreds of years. People weren't rioting in Utah before polygamy was banned there, either.
I doubt you would be making that 'none but tyrants' speech if King George or Congress imposed a BAN on gay civil unions, which arguably have the support of a majority in the U.S. So your demagoguery about tyranny falls flat. You USE the processes of democracy--but you don't believe in that institution, and if you had your way, there would be a tyranny of the righteous, whatever your definition of that is. I don't think any judge should make the law here either, ma'am, but if they did, it would be expanding people's freedom to associate as they see fit, not restricting it. And expanding freedom is rarely a bad thing.
Some people say,"Ah, but marriage is much more than a contract." Yes, it is; but it is treated as if it were much less.
You say, "Obviously, you ... think it's important to regulate what people do in and outside of their homes insofar as the legal status of their spouse is concerned. Of course I do. Marriage law ALWAYS regulates the legal status of putative spouses. That what it's there for. It's illegal to marry a person of the same sex, or a blood relative within certain degrees of consanguinity, or a child, or any person with the intention to deceive or otherwise work some fraud (e.g. in order to change their immigration status.) It is illegal to be married to two persons at the same time.
This is because marriage is NOT just a private personal relationship. It brings in many public aspects having to do with property, inheritance, taxation, insurance, and all the many aspects of child-begetting, child-raising, and child custody when there is fertility involved.
People may think their amours are terribly personal and private, but the very existence of the institution of marriage indicates that there are public interests which can sometimes trump private choices.
Any 2, 3, 4, 6, 20 or 100 friends can form a club, convent, monastery, wicca coven or polygamous patriarchal commune; they can regulate their sexual (or celibate) commitments to each other, and their degree of economic interdependence, by appropriate contract law; and I'll not presume to interfere.
But I think it's improper to call that "marriage," and I'm willing to back up the West's 2-millennia-old one man/one woman definition by law. Those who disagree are equally free to persuade us to deform the definition to accommodate some or all of the groupings listed above.
But their chances of succeeding in this persuasion are about nil, and they know it. They've done the math. They don't have the votes. That's why they're directing their "Long March" through the courts, not the legislatures.
This is dishonest and undemocratic. We don't have to tolerate it.
"What you want is to uphold your version of morality in LAW"
Once again, all law and government are nothing more or less than the codification of the moral vision of those who make the laws.
Mrs. Don-o is every bit as entitled to lobby and vote for the sorts of laws she wants as everyone else.
"never mind the actual negative social consequences of that illegality or its inability to effect any positive change towards your perception of good."
The problem with that argument is that history has repeatedly demonstrated the positive effects of traditional morality and the ability of laws that support it to effect positive change. That much is simply not a matter of opinion, but fact repeatedly proved.