NEW YORK - The Supreme Court transformed America's civil rights landscape in the final week of its 2012 term with a series of landmark decisions heading in opposite directions.

On the one hand, the movement toward marriage equality took a big step forward when the court struck down Section 3 of the Defense of Marriage Act inUnited States v. Windsor, holding that the federal government could no longer deny recognition to legally married same-sex couples. And, by dismissing the appeal in Hollingsworth v. Perry, the court reinstated same-sex marriage in California, which means same sex couples can now get married in 13 states and the District of Columbia.

"We are closer to the day when all loving couples – straight and gay – will be able to marry everywhere in the United States," said Steven R. Shapiro, the national legal director of the American Civil Liberties Union. "The court's decision in Windsor puts it on the right side of history."

In Shelby County v. Holder, on the other hand, the court took a major step backward by striking down a key provision of the Voting Rights Act that determined which states and political subdivisions must obtain approval from the federal government before implementing changes in their voting laws. The preclearance requirement of the Voting Rights Act is widely perceived as one of the most effective civil rights enforcement measures that the country has ever enacted. It was last reauthorized in 2006 by huge bipartisan majorities – indeed, the vote in the Senate was unanimous – based on an extensive legislative record that revealed persistent voting discrimination in the covered states.

"By effectively eliminating the preclearance requirement of the Voting Rights Act, the court has ignored both the lessons of history and the voting discrimination problems of today," Shapiro said. "Congress recognized those problems seven years ago and acted in a bipartisan manner to address them. It urgently needs to do so again. Voting rights are not a partisan issue. They are the foundation of our American democracy."

The ACLU was co-counsel in both Windsor and Shelby County. The ACLU was also counsel or co-counsel in four other cases decided by the Supreme Court this term. In Association for Molecular Pathology v. Myriad Genetics, the court unanimously invalidated patents on two human genes, BRCA1 and BRCA2, associated with an increased risk of hereditary breast and ovarian cancer. In Arizona v. Inter Tribal Council of Arizona, the court struck down an Arizona law requiring prospective voters to produce documentary proof of citizenship in order to register. In Missouri v. McNeely, the court held that the police may not order a warrantless blood test merely because someone has been arrested for drunk driving. And, in Clapper v. Amnesty International USA, the court ruled (before the latest revelations about government surveillance) that our clients did not have standing to challenge broad new surveillance powers authorized by Congress in 2008 because they could not establish with certainty that they had been subject to surveillance – a fact that the government insisted was secret.

Overall, the ACLU participated as direct counsel, or amicus curiae, in nearly a quarter of the court's cases this term, including Fisher v. University of Texas, which failed to produce the clash over race-conscious admissions programs that many had anticipated, leaving the law largely where it was; Agency for International Development v. Alliance for Open Society International, Inc., an important First Amendment ruling limiting the power of government to regulate speech as a condition of funding; and Maryland v. King, which upheld DNA testing for arrestees by characterizing it as simply a way of verifying the identity of the person arrested.

Summarizing the court's momentous last week, Shapiro said, "Shelby County and Windsor both struck down important federal statutes. But the two cases are fundamentally different. Congress is entitled to deference when it uses its constitutional powers to end discrimination, which is why the Voting Rights Act should have been upheld. Congress is not entitled to deference when it passes laws that promote discrimination, which is why DOMA was properly declared unconstitutional."