"Marriage," said Minnesota Republican Michele Bachmann when the Supreme Court handed down its decision banning DOMA, "was created by the hand of God. No man, not even a Supreme Court, can undo what a holy God has instituted."
The kind of marriage this holy God has instituted is described in that book he wrote, the Bible, which is what opponents of gay marriage lean on, implicitly and not, when they talk about "traditional marriage." But the kind of marriages described in the Bible have nothing to do with the one man-one woman principle that the religious right claims is the original, divinely inspired, fully-licensed marriage 1.0.
Let's start with Abraham and his wife, Sarah. After ten years of (geriatric) marriage, Sarah could not get pregnant, so she gave Abraham her maidservant, Hagar, so that, through her, she could have a child with Abraham. She did, and we call him Ishmael. But Ishmael was not born to Sarah, but to her property, Hagar, therefore he did not inherit Abraham's spiritual mantle, as Isaac, the son Abraham and Sarah eventually had, did. Ishmael was sent away with the clothes on his back.
This arrangement was a common one, and Abraham's grandson Jacob had two wives, Rachel and Leah, and then also had kids with their handmaids, Bilhah and Zilpah. And this, in fact, was the traditional, Biblical model of marriage. There was the main wife or wives—the Sarahs, the Rachels, and the Leahs—and their handmaids—the Hagars. The husband owed the main wife certain financial support and protection, she had a certain legal status, but the handmaids were just there to pick up the pace when the main wives slacked in their childbearing. They, and their children, were lesser legal entities, and were not entitled to the same benefits and inheritances. In fact, the children of the handmaids belonged in some way to the wives. Both Sarah and Rachel describe having their husband father a child with their servant girl as "being built up through her."
And then there's the straight-up polygamy. Jacob had two wives, acquiring the second one after being tricked into marrying the first one. Esau, Jacob's older brother, had three wives. David had at least five wives and countless fecund concubines. The wise King Solomon had "seven hundred wives, princesses, and three hundred concubines." Even Moses had a second, Cushite wife, and God had his back, punishing Moses's siblings, Miriam and Aaron, for speaking out against the marriage. In Deuteronomy, there is even a legal provision for how to split up the inheritance between sons born to two wives, rather than to a wife (isha, in Hebrew) and a handmaiden (pilegesh): The firstborn, even if born to the wife you love less, still gets double what the son, born to the wife you love more, inherits.
So there you have it, traditional marriage from a holy God. Here's hoping we'll never have to experience such tradition.