In recent years, the issue of same-sex relationships and marriage has become an important political debate. Homosexuality as a practice has always existed within Western culture. It has usually been disparaged, stigmatized, and regulated by law with varying levels of disapproval throughout history. While the Greeks considered homosexuality as natural as heterosexuality, Christians have condemned same-sex relations as animal lust, sinful, and unnatural. An example of Christian disapproval was the passage of laws criminalizing homosexual activities and banning same-sex marriages. The Christian perspective was later incorporated into English common law and eventually into American law. The widespread disapproval of homosexuals within the United States has created an environment of pervasive discrimination against gays and lesbians. Most Americans now believe that government should protect the rights of minorities, women, persons with disabilities, and others. But there is great disagreement over  whether the Constitution permits government to regulate private homosexual relations and deny civil marriage to same-sex couples.

Since the 1970s, the gay community has challenged statutes regulating homosexual relations and particularly laws making sodomy a crime. The first case to reach the Supreme Court was Bowers v. Hardwick (1986). It arose when an Atlanta police officer, who was serving a warrant for an unpaid fine, was admitted into the home of Michael Hardwick and found him in his bedroom committing sodomy with another man. He was arrested, but not prosecuted. Hardwick brought suit on the grounds that law violated his right to privacy because his sexual activity was a private and intimate association between consenting adults. A sharply divided Court refused to extend constitutional protection to homosexuals to engage in sodomy. Speaking for the majority, Justice Byron White relied on the historical ubiquity of sodomy laws and the absence of any express constitutional right protecting such conduct. He held that "proscriptions against sodomy have ancient roots. Sodomy was a criminal offense at common law and was forbidden by the laws of the original thirteen states when they ratified the Bill of Rights. In 1868, when the Fourteenth Amendment was ratified, all 50 states outlawed sodomy, and today, 24 states and the District of Columbia continue to provide criminal penalties for sodomy performed in private and between consenting adults. Against this background, to claim that a right to engage in such conduct is 'deeply rooted in this Nation's history and tradition' or 'implicit in the concept of ordered liberty ' is, at best facetious." Justice White concluded that neither the text of the Constitution nor any philosophy of liberty provides a judicial basis for independently reviewing the legislative decision to criminalize homosexual conduct. He explained that absent such a constitutional right the courts should defer to the discretion of the legislature to regulate the morality of its own citizens. "The law," held Justice White, "is constantly based on notions of morality, and if all laws representing essentially moral choices are to be invalidated under the due process clause, the courts will be very busy indeed." The Bowers decision suggested that laws prohibiting homosexual conduct require no more legal justification than a belief by the majority that such conduct is immoral.

But four justices strongly disagreed with the majority. Justice Blackmun contended that "this case is about 'the most comprehensive of rights and the right most valued by civilized men,' namely 'the right to be let alone.'" He criticized the majority for deciding that "the statute is valid essentially because 'the laws of many States still make such conduct illegal and have done so for a very long time.' The fact that the moral judgments expressed by the statutes may be natural and familiar," continued Justice Blackmun, "ought not to conclude our judgment upon the question whether statutes embodying them conflict with the Constitution. Like Justice Holmes, I believe 'it is revolting to have no better reason for a rule of law than that so it was laid down in the time of Henry IV. It is still more revolting if the grounds on which it was laid down have vanished long since, and the rule simply persists from blind imitation of the past.'" He then argued that the Constitution protects the right of individuals to make decisions about the most private aspects of their lives, "not because they contribute, in some direct and material way, to the public welfare, but because they form so central a part of the individual's life." He further stressed that "the very concept of privacy embodies the moral fact that a person belongs to himself and not others nor to society as a whole." Justice Blackmun reminded the majority that homosexual relations involve personal intimacy and realize important human needs: "Only the most willful blindness could obscure the fact that sexual intimacy is a sensitive, key relationship of human existence, central to family life, community welfare, and the development of human personality. The fact that individuals define themselves in a significant way through their intimate sexual relationships with others suggests, in a Nation as diverse as ours, that there may be many 'right' ways of conducting those sexual relationships, and that much of the richness of a relationship will come from the freedom an individual has to choose the form and nature of these intensely personal bonds." The dissent also pointed out that "special protection" is accorded to people to satisfy their intellectual and emotional needs in the sanctity of the home, provided their choices pose no danger to the rights or safety of others. Justice Blackmun and his colleagues concluded that the state's effort to regulate morality is not a compelling enough interest to deny individuals the right to decide for themselves whether to engage in harmless forms of private, consensual sexual activity. Later, the liberal philosophy of the dissenters was embraced by several state tribunals. New York, Montana, Georgia, and other state supreme courts have subsequently found a right to privacy in their own state constitutions broad enough to protect consensual sodomy between adults.

Recently, the issue of whether same-sex marriage should be legally recognized has emerged at the center of a national debate. Many Americans consider marriage to be a sacred and important union between a man and woman. Others maintain that homosexuals have a personal right to be legally married and receive the same legal protections afforded to heterosexual couples. They argue that at the heart of the civil union is an emotional, psychological, and financial bond between two people regardless of their sexual orientation. Gay couples have unsuccessfully challenged traditional marriage laws in Minnesota, Kentucky, Washington and other states. In Baehr v. Lewin (1993), however, the Hawaii Supreme Court held that denying the right to marry to same-sex couples violated the equal protection clause of the state constitution. The majority rejected the claim that homosexuals have a fundamental right to marry, but found that the state had created a sex-based classification by restricting the right to marry to heterosexual couples without a narrowly tailored means to achieve a compelling government interest. The majority interpreted the state constitution to require public officials to issue marriage licenses to same-sex couples. The Hawaii Legislature acted promptly by amending the state's marriage law to grant the legal recognition of marriage to same-sex couples. A similar result occurred within Vermont. In Baker v. Vermont (1999), the Vermont Supreme Court held that prohibiting same-sex marriages violates the equal protection clause of the state constitution. The Vermont Legislature responded by extending to same-sex couples entering into civil unions the protections and privileges of civil marriage.

Baehr and Baker had national implications of constitutional proportions. Article IV, Section One of the Constitution stipulates that "Full Faith and Credit shall be given in each state to the public Acts, Records, and judicial Proceedings of every other State." The full faith and credit clause requires the states to recognize the records or acts of other states, such as driver's or marriage licenses. Same-sex marriages from Hawaii or Vermont would have to be honored by other states. Some feared that gay couples could go to Hawaii and Vermont to get married, return to their home state, and enjoy the same legal benefits provided for married heterosexual couples, including inheritance, housing, taxation, and adoption. In anticipation of this possibility, a number of states have enacted legislation banning out of state same-sex marriages as contrary to public policy. Congress also passed the Defense of Marriage Act (1997), relieving states of any obligation under the Constitution to recognize same-sex marriages from other states. Congress took this unique step by introducing into the United States Code a new federal definition of marriage. The bill was overwhelmingly supported by both houses of Congress and promptly signed into law by President Bill Clinton. In 1998, the voters of Hawaii also amended their state constitution to permit the legislature to forbid same-sex marriage. Before the adoption of the new law, the Hawaii Supreme Court upheld the old law restricting marriage licenses to only heterosexual couples. Does the democratic principle of showing equal concern and respect to the choices of everyone require the state to extend the same rights and responsibilities of marriage to homosexual couples?