DOMA Opinion Page 16 on:
Supreme Court DOMA Ruling: Read Full Decision Here [DOC] | HEAVY
..."In order to assess the validity of that intervention it is necessary to discuss the extent of the state power and authority over marriage as a matter of history and tradition. State laws defining and regulating marriage, of course, must respect the constitutional rights of persons,see, e.g., Loving v. Virginia, 388 U. S. 1 (1967); but, subject to those guarantees, “
regulation of domestic relations” is“an area that has long been regarded as a virtually exclusive province of the States....
...The recognition of civil marriages is central to state domestic relations law applicable to its residents and citizens. See Williams v. North Carolina, 317 U. S. 287,298 (1942) (“Each state as a sovereign has a rightful and legitimate concern in the marital status of persons domi-ciled within its borders”

. The definition of marriage is the foundation of the State’s broader authority to regulate the subject of domestic relations with respect to the“[p]rotection of offspring, property interests, and the enforcement of marital responsibilities.”
Ibid.
“[T]he states, at the time of the adoption of the Constitution, possessed full power over the subject of marriage and divorce. . . [and] the Constitution delegated no authority to the Government of the United States on the subject of marriage and divorce.”...
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The significance of state responsibilities for the definition and regulation of marriage dates to the Nation’s beginning; for “when the Constitution was adopted the common understanding was that the domestic relations of husband and wife and parent and child were matters reserved to the States.” Ohio ex rel. Popovici v. Agler, 280U. S. 379, 383–384 (1930).
Marriage laws vary in some respects from State to State. For example, the required minimum age is 16 in Vermont, but only 13 in New Hampshire. Compare Vt. Stat. Ann., Tit. 18, §5142 (2012),with N. H. Rev. Stat. Ann. §457:4 (West Supp. 2012).Likewise the permissible degree of consanguinity can vary...
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In acting first to recognize and then
to allow same-sex marriages, New York was responding “to the initiative of those who [sought] a voice in shaping the destiny of their own times.” Bond v. United States, 564 U. S. ___, ___ (2011) (slip op., at 9).
These actions were without doubt a proper exercise of its sovereign authority within our federal system, all in the way that the Framers of the Constitution intended. The dynamics of state government in the federal system are to allow the formation of consensus respecting the way the members of a discrete community treat each other in their daily contact and constant interaction with each other....