The Defense of Marriage Act (DOMA) is a federal law designed to give states the right to refuse recognition of a same-sex marriage approved by another state. It also defines marriage as a union between a man and woman for the purposes of federal law.

The act is divided into two major sections. The first section deals with authority given to the states, and says, "No state, territory, or possession of the United States, or Indian tribe, shall be required to give effect to any public act, record, or judicial proceeding of any other state, territory, possession, or tribe respecting a relationship between persons of the same sex that is treated as a marriage under the laws of such other state, territory, possession, or tribe, or a right or claim arising from such relationship."

The second section provides a federal definition of marriage as an institution between one man and one woman, with the word "spouse" referring only to a person of the opposite sex who is a husband or wife.

Republican Rep. Bob Barr of Georgia introduced DOMA in May 1996. The bill passed the House of Representatives by a vote of 342-67 and the Senate by a vote of 85-14. President Clinton signed the bill on Sept. 21, 1996.

Since 1996, legal experts and political leaders have debated the constitutionality of DOMA. Some have argued that it clearly violates the "full faith and credit" clause of the U.S. Constitution, which reads, "Full faith and credit shall be given in each state to the public acts, records and judicial proceedings of every other state. And the Congress may by general laws prescribe the manner in which such acts, records and proceedings shall be proved, and the effect thereof."

When President George W. Bush announced support for a constitutional amendment that would define marriage as a union between a man and a woman, he referenced what he sees as DOMA's potential vulnerability at the hands of what he termed "activist" judges, under the full faith and credit clause.

"The Constitution says that full faith and credit shall be given in each state to the public acts and records and judicial proceedings of every other state," the president said. "Those who want to change the meaning of marriage will claim that this provision requires all states and cities to recognize same-sex marriages performed anywhere in America. Congress attempted to address this problem in the Defense of Marriage Act, by declaring that no state must accept another state's definition of marriage. My administration will vigorously defend this act of Congress. Yet there is no assurance that the Defense of Marriage Act will not, itself, be struck down by activist courts."

Whether or not DOMA squares with the Constitution is also a matter of debate among legal scholars. Some have said DOMA should not be subject to the full faith and credit clause because the clause itself gives Congress the right to control the "effect" of the agreements that fall under it.

Pepperdine University law professor Douglas Kmiec, who has expressed support for the president's plan to constitutionally define marriage as the union of a man and a woman, told the NewsHour in July 2003 that the full faith and credit clause is "is subject to a very important qualification, and the qualification is that Congress can define the manner and effect of the judgments from the other state."

University of Pittsburgh law professor Rhonda Wasserman disagrees. Wasserman told the Online NewsHour that other legal scholars have posited the "more convincing argument" that the second half of the full faith and credit clause "should not be read to permit a selective withdrawal of recognition for only same-sex marriages."

Despite the constitutional issues surrounding DOMA, however, supporters of the president's plan believe that a constitutional amendment is now needed in addition to DOMA, due to recent court rulings and legislative action.

"This is a subject upon which clarity is needed and not confusion," Kmiec told the NewsHour in February 2004.

Since DOMA's adoption, legal experts have also debated whether the act's granting of the ostensible right not to recognize marriage from another state was necessary in the first place. A long-held standard of American case law known as the "public policy exception" exempts any state from recognizing a law from another state if it is found to be "offensive" to the receiving state's public policy. This standard is included in what is known as "choice of law" doctrine. "Choice of law" guides judges when they must consider conflicting statutes between two states or nations.

California Western School of Law professor and same-sex marriage rights advocate Barbara Cox told the Online NewsHour that, historically, with the public policy exception in place, states have ruled more often on the side of recognition of marriages performed in another state in order to maintain stability.

"If a marriage was valid where celebrated, then it was considered valid everywhere. Because of the strong public policies behind this general rule, there exists in the United States an overwhelming tendency to validate out-of-state marriages, even if those marriages would not have been permitted in the couple's home state," says Cox. "The reasons for doing this are to confirm the parties' expectations, to provide stability in an area where stability is vital (particularly because of children, property, and other financial and medical issues), and to avoid the potentially 'hideous problems' that would result if the legality of a couple's marriage varied as the couple crossed the country."

Cox argues that DOMA goes beyond the public policy exception by allowing states to "treat the marriages of same-sex couples with disdain and refuse to recognize them, even if a particular state has always recognized the out-of-state marriages of its citizens who were similarly prevented from marrying in their home state."

Cox has asserted that if DOMA did not exist, more same-sex couples would be extended legal marriages under marriage recognition case law.

Since DOMA's passage, however, some 38 states have passed their own versions of DOMA, making the definition of marriage as the union of a man and a woman part of their public policy and explicitly stating that same-sex marriages from other states will not be legally recognized. Some legal experts have said that under the "public policy exception" standard, these states can now deny recognition of marriages performed elsewhere on the grounds of precedent in case law -- without reference to the federal DOMA law. This, they say, reverses the tendency toward recognition under case law.

"While choice of law doctrine has usually favored the recognition of marriages that are valid in the celebration state, this has never been an immutable rule and has long been the subject of the public policy limitation," Patrick Borchers, dean of Creighton University Law School, wrote in a book titled, "Marriage and Same-Sex Unions: A Debate." "More than half of the states now have statutes that positively prohibit recognition of same-sex marriages, and others may well apply the public policy exception to the celebration rule," he wrote.

This means, according to Borchers, that states with their own DOMA statutes would have solid legal grounds on which to deny recognition of same sex marriage.

Wasserman similarly argues that if states alone had instituted DOMA laws then the federal DOMA statute may not have been necessary at all. However, she also asserts an important condition in the type of public act being considered by the receiving state.

"If states may invoke the public policy exception to avoid recognition of same-sex marriages performed elsewhere, then DOMA is largely unnecessary, for many states have enacted statutes that clearly state a public policy to limit marriage to opposite-sex couples," said Wasserman. "But one must ask whether states really are free to employ the public policy exception."

Wasserman said that the public policy exception only applies to the laws of other states. "Judgments," that is, judicial proceedings from another state, must be recognized. Marriages are not usually viewed as judgments.

"If, however, a court were to render a judgment that recognized the validity of a same-sex marriage, then -- in the absence of DOMA -- other states would have to recognize that judgment notwithstanding their policy against same-sex marriage," she said. "Thus, DOMA (if constitutional) would permit states to disregard judgments that they otherwise would be required to recognize."

Some same-sex marriage advocates have said this unfairly singles out same-sex couples. Cox has written that the federal and state DOMA laws might be challenged as a violation of equal protection rights guaranteed under the Constitution's 14th Amendment.

This reasoning leads naturally to a debate about the nature and definition of marriage and the meaning of gender in society. Advocates of same-sex marriage believe that the federal and state DOMA statutes are constitutionally vulnerable because they lead to unequal treatment of same-sex couples.

Opponents of same-sex marriage have argued that those laws are safe and appropriate in that marriage, by its nature, is a union between a man and a woman. Therefore, they argue, same-sex relationships, by their nature, are something other than marriage. They also assert that the state has an interest in maintaining and protecting marriage as a fundamental institution of society. Instead of federal and state DOMA laws and/or a constitutional amendment denying rights, opponents of same sex marriage believe they affirm marriage.

"[S]tates have preferred marriage, have given it a position of prominence because it does some very important things," Kmiec said. "It supplies new members to our community and it supplies a household that is the most important educator for our community. In this sense it's not a denial of right; it is an affirmation of what is important."

-- By Jason Manning, Online NewsHour