Opinion of the Court
defined as a union between opposite-sex partners. So too in 1996, Congress passed the Defense of Marriage Act (DOMA), 110 Stat. 2419, defining marriage for all federal-law purposes as “only a legal union between one man and one woman as husband and wife.” 1 U. S. C. §7.
The new and widespread discussion of the subject led other States to a different conclusion. In 2003, the Supreme Judicial Court of Massachusetts held the State’s Constitution guaranteed same-sex couples the right to marry. See Goodridge v. Department of Public Health, 440 Mass. 309, 798 N. E. 2d 941 (2003). After that ruling, some additional States granted marriage rights to same-sex couples, either through judicial or legislative processes. These decisions and statutes are cited in Appendix B, infra. Two Terms ago, in United States v. Windsor, 570 U. S. ___ (2013), this Court invalidated DOMA to the extent it barred the Federal Government from treating same-sex marriages as valid even when they were lawful in the State where they were licensed. DOMA, the Court held, impermissibly disparaged those same-sex couples “who wanted to affirm their commitment to one another before their children, their family, their friends, and their community.” Id., at ___ (slip op., at 14).
Numerous cases about same-sex marriage have reached the United States Courts of Appeals in recent years. In accordance with the judicial duty to base their decisions on principled reasons and neutral discussions, without scornful or disparaging commentary, courts have written a substantial body of law considering all sides of these issues. That case law helps to explain and formulate the underlying principles this Court now must consider. With the exception of the opinion here under review and one other, see Citizens for Equal Protection v. Bruning, 455 F. 3d 859, 864–868 (CA8 2006), the Courts of Appeals have held that excluding same-sex couples from marriage violates the Constitution. There also have been many
