"Marriage is the legally binding life-long contract between two sexual partners that exists strictly because the sexual activity produces children who require long-range nurture and education."
Actually, marriage does and has existed for a variety of reasons over the centuries. Producing children is no longer necessary nor is it true of every marriage. Most people get married out of love, and some either do not want children or incapable of having any due to age or infertility. Does that make their marriage invalid?
"The procreation of the citizenry is what makes "marriage" unique among all human relationships"
And if you looked around, you would realize that procreation and marriage are no longer as linked as they used to be. As much as you people deplore sex "before" marriage, it happens, and children are born from it. And yet, there is no guarantee that the people involved get married. Why? Well the first reason could be that sexual relationships, i.e. procreation, do not necessarily overlap with intimate, loving relationships, i.e. marriage as it should be in order to last. The second reason is simply because there is no compelling reason for copulating couples to marry given the high incidence of divorce, and when co-habitation works in well enough like a marriage relationship, though without the legal rights.
"The long-range aspect of the "marriage contract" arises from the right children have to be nurtured into adulthood by the sexual partners that created them."
Not really the "right" that children have to be raised by their parents, but rather the fact that the parents of a child are responsible for giving birth to the child, and thus need to take care of it, because (most likely) no one else will. However, if there is someone who can raise the child and is willing (adoption), parents are more than free to dump the child on them, with the child's "rights" intact. In reality, the marriage contract may have served the purpose of assuring the production and raising of children, but it no longer needs to serve that purpose in our society, where it has changed into an agreement between two people in love with one another who want to live the rest of their lives together, and get certain legal rights due to that. That's what marriage is now; it is no longer a reproduction quota, if it ever was.
