“One of the cases, from California, could establish or reject a constitutional right to same-sex marriage. The justices could also rule on narrower grounds that would apply only to marriages in California.
The second case, from New York, challenges a federal law that requires the federal government to deny benefits to gay and lesbian couples married in states that allow such unions.
The court’s move against the backdrop of a rapid shift in public attitudes about same-sex marriage, with recent polls indicating that a majority of Americans support allowing such unions. After the elections last month, the number of states authorizing same-sex marriage increased by half to nine.”