Proposition 8
Origin: Passed in 2008 by 52 percent of California voters.
Effect: Amended the state Constitution to make same-sex marriage illegal.
Plaintiffs: A lesbian couple, Kristin Perry and Sandra Stier, and a gay couple, Paul Katami and Jeffrey Zarrillo.
Defendant: The state of California, which declined to defend the measure in court. (A coalition called ProtectMarriage.com will argue to uphold the ban.)
Rulings to date: In 2010, U.S. District Judge Vaughn Walker struck down the ban. In February 2012, the Ninth U.S. Circuit Court of Appeals in San Francisco upheld his decision.
Defense of Marriage Act
Origin: Passed by Congress in 1996 with margins of 342-67 in the House and 85-14 in the Senate.
Effect: Defines marriage as between a man and a woman and denies more than 1,100 federal benefits to gay and lesbian couples who are legally married.
Plaintiff: Edie Windsor, an 83-year-old New York woman who paid $363,053 in estate taxes because the IRS did not recognize her marriage to another woman.
Defendant: The Obama administration, which has chosen not to defend the law. (Former U.S. Solicitor General Paul Clement argue to uphold it.)
Rulings to date: In June 2012, U.S. District Judge Barbara Jones found Section 3 of DOMA to be unconstitutional. The Second U.S. Circuit Court of Appeals in New York upheld her decision in October.
