By a 5 to 4 vote, the Supreme Court ruled today that the United States constitution requires states to recognize marriages between couples of the same sex. Justice Kennedy, joined by Justices Kagan, Sotomayor, Breyer, and Ginsburg, wrote for the majority. Chief Justice Roberts and Justices Scalia, Thomas, and Alito dissented.
In Justice Scalia's dissent, he writes that although "substance of today’s decree is not of immense personal importance to me," the decision represents a "threat to American democracy":
I join THE CHIEF JUSTICE’s opinion in full. I write separately to call attention to this Court’s threat to American democracy. The substance of today’s decree is not of immense personal importance to me. The law can recognize as marriage whatever sexual attachments and living arrangements it wishes, and can accord them favorable civil consequences, from tax treatment to rights of inheritance. Those civil consequences—and the public approval that conferring the name of marriage evidences—can perhaps have adverse social effects, but no more adverse than the effects of many other controversial laws. So it is not of special importance to me what the law says about marriage. It is of overwhelming importance, however, who it is that rules me. Today’s decree says that my Ruler, and the Ruler of 320 million Americans coast-to-coast, is a majority of the nine lawyers on the Supreme Court. The opinion in these cases is the furthest extension in fact— and the furthest extension one can even imagine—of the Court’s claimed power to create “liberties” that the Constitution and its Amendments neglect to mention. This practice of constitutional revision by an unelected committee of nine, always accompanied (as it is today) by extravagant praise of liberty, robs the People of the most important liberty they asserted in the Declaration of Independence and won in the Revolution of 1776: the freedom to govern themselves. Until the courts put a stop to it, public debate over same-sex marriage displayed American democracy at its best. Individuals on both sides of the issue passionately, but respectfully, attempted to persuade their fellow citizens to accept their views. Americans considered the arguments and put the question to a vote. The electorates of 11 States, either directly or through their representatives, chose to expand the traditional definition of marriage. Many more decided not to.1 Win or lose, advocates for both sides continued pressing their cases, secure in the knowledge that an electoral loss can be negated by a later electoral win. That is exactly how our system of government is supposed to work. [...]
You can read the full majority and minority opinions here.