"The recognition of same-sex marriages generates debate on both the federal and state levels. Either legislatively or judicially, same-sex marriage is legal in seven states. Other states allow civil unions or domestic partnerships, which may provide similar state-level rights and/or benefits. Many states have statutes or constitutional amendments limiting marriage to one man and one woman. These state-level variations raise questions about the validity of such unions outside the contracted jurisdiction and have bearing on the distribution of federal benefits. […] This report discusses DOMA [Defense of Marriage Act] and legal challenges to it. It reviews legal principles applied to determine the validity of a marriage contracted in another state and surveys the various approaches employed by states to enable or to prevent same-sex marriage. It also examines previous Congressional resolutions proposing a constitutional amendment and limiting federal courts' jurisdiction to hear or determine any question pertaining to the interpretation of DOMA."
CRS Report for Congress, RL31994