United States v. Windsor (Defense of Marriage Act)In United States v. Windsor, Justice Anthony Kennedy wrote the majority opinion finding that the federal Defense of Marriage Act "is unconstitutional as a deprivation of the equal liberty persons that is protected by the Fifth Amendment." The Defense of Marriage Act prevented Petitioner Edith Windsor from benefiting from the surviving spouse provisions of federal estate tax law.
That opinion as well as the dissents of Justices Roberts, Scalia, and Alito can be found here.
For further reading, here is a 2004 report prepared by the Government Accountability Office that lists all of the then 1,138 statutes affected by the Defense of Marriage Act.
Hollingsworth v. Perry (California's Proposition 8)In the second case, Hollingsworth v. Perry, the Supreme Court refused to decide the issue of the constitutionality of Proposition 8, a 2008 California voter-passed initiative amending the California Constitution to define marriage as between "a man and a woman." Chief Justice Roberts, writing for the majority, explained that the court did not have the jurisdiction to decide the constitutionality of the law.
When California same-sex couples who wished to marry brought suit in federal district court to challenge Proposition 8, the California officials responsible for enforcing it (including then governor, Arnold Schwarzenegger) refused to defend the law. The District Court then allowed the official Proposition 8 supporters to intervene and defend its constitutionality. After a bench trial, the District Court declared Proposition 8 unconstitutional, and the Ninth Circuit eventually affirmed this decision. The Supreme Court case hinged on the issue of the standing of these non-government officials to defend a state statute in federal court.
In today's opinion, Chief Justice Roberts reminded us that the Supreme Court has "never before upheld the standing of a private party to defend the constitutionality of a state statute when state officials have chosen not to." He went on further to say that "[w]e decline to do so for the first time here" and concluded that the Ninth Circuit did not have the jurisdiction to consider the original appeal, vacating its decision, and remanding it back to the Ninth Circuit with instructions to dismiss the appeal for lack of jurisdiction.
The Supreme Court decision in Hollingsworth v. Perry, including the majority opinion of Chief Justice Roberts and a dissent by Justice Kennedy, can be found here.
For further understanding of the procedural history of this case, take a look at the original complaint in Perry et al. v. Schwarzenegger et al., filed in U.S. District Court for the Northern District of California. This and other documents filed in the District Court case can be found for free through RECAP, a service that archives publicly available documents filed in many federal courts and downloaded through PACER.