Our prior cases make two propositions abundantly clear. First, the fact that the governing majority in a State has traditionally viewed a particular practice as immoral is not a sufficient reason for upholding a law prohibiting the practice; neither history nor tradition could save a law prohibiting miscegenation from constitutional attack. Second, individual decisions by married persons, concerning the intimacies of their physical relationship, even when not intended to produce offspring, are a form of “liberty” protected by the Due Process Clause of the Fourteenth Amendment. Moreover, this protection extends to intimate choices by unmarried as well as married persons.
-- Lawrence v. Texas (quoting Justice Stevens)
Lawrence overruled Bowers v. Hardwick, which had a more limited view of intimate association. Griswold v. Connecticut started a line of cases that protected sexual intimacy and the rights of families (such as parental rights and a grandmother living with nephews). The right of unmarried people (even minors) to buy contraceptives was also recognized, but the Supreme Court was wary about taking cases that took the point that far. Various lower court opinions on such questions as cohabitation, fornication, female teachers breaking "morals" requirements and so forth underlined the issues raised by the sexual revolution. Lawrence in effect cemented the deal.
Society has built off more limited ideas that such choices should be tied to marriage. In the days of Jane Austin, see Emma, just writing to a member of the opposite sex before you were at least engaged could be a major social taboo. Now, unless you live in Saudi Arabia, such intersexual socializing is accepted. The importance of equality, including in respect to same sex marriage, should not lead people to have a "one size fits all" mentality as shown by another major gay/lesbian activist [Paula L. Ettelbrick] who recently died:
“When analyzed from the standpoint of civil rights, certainly lesbians and gay men should have the right to marry,” she wrote in the fall 1989 issue of Out/Look magazine as part of a debate with Thomas B. Stoddard, a colleague at Lambda who strongly favored same-sex marriage. “But obtaining a right does not always result in justice.”
I sometimes read during same sex marriage debates that the best path was simply (uh huh) to end state sponsored marriage overall, a type of major structural change that is more late night college debate topic than likely to happen any time soon.* But, it is not totally off the wall, since in various ways, marriage is not required for those in long term relationships, who raise families or join together for various purposes, such as two siblings who have a home and care for each other. And, the law in various ways -- including definitions of "household" for rental purposes -- recognizes the fact. There are various "beyond marriage" movements noting the fact, see also Beyond (Straight and Gay) Marriage: Valuing All Families under the Law. Amazon notes:
Topics such as inheritance, tax consequences, workers' compensation death benefits, social security, probate, adoption and health care, plus their impact the diversity of today's family units are simplified for the reader.
The movement for liberty and equality for all is not about any one issue, important as it might be, and those with a broad vision are to be respected. After all, even Rachel Maddow, who has had a long term same sex relationship with her partner, is not only a stronger supporter of same sex marriage rights, but doesn't think the choice is right for her at the moment. Maddow in a recent interview said she was wary of one size fits all sentiment on that front. Many long term unmarried different sex couples would fully agree. And, NPR recently had a nice segment about an unconventional (heterosexual) couple.
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* If a candidate, such as Mitt Romney, opposes same sex "marriage," they need to be asked if they think civil unions are wrong as well, including when governmental benefits such as social security and bankrutpcy are involved. A recent answer that he is supportive of giving them hospital visitation rights doesn't quite do it.