The Defense of Marriage Act, signed by Bill Clinton in 1996, bars the federal government from recognizing same-sex marriages authorized by states, and allows states not to recognize same-sex marriages from other states. It was overturned 5-4 in U.S. v. Windsor, written by Kennedy.
That means that same-sex couples can file joint federal tax returns and qualify for the spousal exemption in federal estate tax.
It may mean that same-sex couples can get divorces in states that don't allow them to marry. It may overturn any state law barring same-sex couples from adopting children. Other wrinkles are left to the states to sort out.
But the court was unwilling to impose same-sex marriage on states that don't want it. That was the practical effect of Perry v. Hollingsworth, which left in place a California federal trial court decision overturning California's Proposition 8, which banned same-sex marriage.
The state declined to defend the law on appeal, and the chief justice wrote that the private parties who appealed lacked the standing to do so. He got the votes of the unusual coalition of justices Antonin Scalia, Ruth Bader Ginsburg, Stephen Breyer and Elena Kagan.
Ginsburg supports Roe v. Wade but has spoken with some concern about the furor the court caused by legalizing abortion across the nation. She and some colleagues may have dreaded a similar furor if the court legalized same-sex marriage everywhere.
The practical effect is that California now has same-sex marriage. But polls indicate that California voters stood ready to reverse Proposition 8's narrow 52 to 48 percent margin if the issue again got on the ballot.
These decisions, which tend to restrain branches of government from interfering with each other, were the product of no single coalition. No justice voted with the majority in all four cases, but each voted with the majority in two or three. A thought-provoking session.