As defined by the Defense of Marriage Act, marriage is a "legal union between one man and one woman as husband and wife," and spouse refers "only to a person of the opposite sex who is a husband or a wife."
Passed by Congress in 1996 and signed into law by then-president Bill Clinton, DOMA's unambiguous definition of marriage denies same-sex couples--whether states recognize their relationships or not--more than 1,100 federal spousal benefits and obligations, including Social Security, federal civilian and military service benefits, and family and medical leave, according to the U.S. Government Accountability Office.
"[It] is federal discrimination, pure and simple," …