The Supreme Court was expected to issue rulings on Wednesday in two high-profile gay marriage cases in its latest review of discrimination based on sexual orientation.
It has been a decade since the court last took up a gay-rights dispute. That 2003 case from Texas and the court's two earlier gay-rights decisions were closely fought and produced strong dissenting opinions.
In a lesser known case, the 1972 Baker v. Nelson, the court summarily dismissed an appeal against a Minnesota Supreme Court decision upholding a law that restricted marriage to opposite-sex couples. The U.S. Supreme Court wrote no opinion and said only that the matter lacked a "substantial federal question." Opponents of same-sex marriage have cited that court action to bolster their position, but lower courts that have ruled on the matter have not found it determinative.
Here is how the justices divided in past major cases:
* Bowers v. Hardwick, 1986
Facts: Michael Hardwick was arrested for engaging in intimate sexual conduct with another man in Hardwick's Atlanta home, violating a Georgia ban on oral and anal sex for homosexual and heterosexual couples. The charges against Hardwick were dropped, but he challenged the sodomy prohibition as unconstitutional when enforced against same-sex relations.
Supreme Court vote: 5-4 to uphold the law
Majority: In an opinion by Justice Byron White, the court said no right to privacy existed for homosexual relations. White emphasized that "proscriptions against that conduct have ancient roots" and said legislatures often pass laws "based on notions of morality." The court spurned Hardwick's claim that intimate conduct in a private home should not be subject to criminal law. "Victimless crimes, such as the possession and use of illegal drugs, do not escape the law where they are committed at home," White wrote, joined by Chief Justice Warren Burger and Justices Lewis Powell, William Rehnquist and Sandra Day O'Connor.
Dissent: Justice Harry Blackmun said the Georgia law wrongly denied gay men and women choices about their private, consensual activities. "This case involves no real interference with the rights of others, for the mere knowledge that other individuals do not adhere to one's value system cannot be a legally cognizable interest, let alone an interest that can justify invading the houses, hearts, and minds of citizens who choose to live their lives differently," Blackmun wrote, joined by Justices William Brennan, Thurgood Marshall and John Paul Stevens.
(None of the nine justices who heard Bowers v. Hardwick is still on the court and the ruling was later struck down in 2003.)
* Romer v. Evans, 1996
Facts: After Aspen, Boulder and some other municipalities in Colorado banned discrimination based on sexual orientation, state voters adopted Amendment 2. That 1992 ballot measure voided those ordinances and prohibited government entities in Colorado from protecting gays against bias, for example in housing, education and employment. Among the people who challenged the law was Richard Evans, an AIDS counselor in the Denver mayor's office.
Supreme Court vote: 6-3 to strike down Amendment 2.
Majority: Justice Anthony Kennedy rejected the state's argument that the law merely denied gays "special rights." Rather, he said, the measure put them at a disadvantage and was "born of animosity," with no legitimate governmental purpose. Declaring that Amendment 2 violated the Constitution's guarantee of equal protection, he wrote, "A state cannot so deem a class of persons a stranger to its laws." He was joined by Justices Stevens, O'Connor, David Souter, Ruth Bader Ginsburg and Stephen Breyer.
Dissent: Justice Antonin Scalia insisted the state measure was "a rather modest attempt by seemingly tolerant Coloradans to preserve traditional sexual mores against the efforts of a politically powerful minority to revise those mores through use of the laws." Condemning the majority opinion for being "long on emotive utterance" and "short on relevant legal citation," Scalia said its decision had no foundation in U.S. constitutional law. He was joined by Chief Justice Rehnquist and Justice Clarence Thomas.
(Since the decision, Rehnquist has been succeeded by Chief Justice John Roberts, O'Connor by Justice Samuel Alito, Souter by Justice Sonia Sotomayor, and Stevens by Justice Elena Kagan.)
* Lawrence v. Texas, 2003
Facts: Houston police officers responding to a reported weapons disturbance entered the apartment of John Lawrence and found him engaged in a sexual act with Tyron Garner, violating a Texas law that criminalized oral and anal sex between same-sex couples.
Supreme Court vote: 6-3 to strike down the law; five justices spurned the 1986 Bowers v. Hardwick rationale and declared the Texas sodomy ban violated the right to privacy; O'Connor, who had been in the majority in 1986, voted against the Texas statute on a separate rationale based on equal protection of the law.
Majority: Declaring that the court failed to appreciate the liberty at stake back in 1986, Justice Kennedy said the Constitution protects the intimate relations of homosexuals just as it does heterosexuals. He said Lawrence and Garner were "entitled to respect for their private lives. The state cannot demean their existence or control their destiny by making their private sexual conduct a crime." Kennedy was joined in full by Justices Stevens, Souter, Ginsburg and Breyer; O'Connor joined only the bottom line to void the law.
Dissent: Justice Scalia again wrote for dissenters. He said the majority wrongly expanded past cases involving due process of law and said, "Let me be clear that I have nothing against homosexuals, or any other group, promoting their agenda through normal democratic means. Social perceptions of sexual and other morality change over time, and every group has the right to persuade its fellow citizens that its view of such matters is the best. ... But persuading one's fellow citizens is one thing, and imposing one's views in absence of democratic majority will is something else." He was joined by Rehnquist and Thomas.
(Reporting by Joan Biskupic; Editing by Howard Goller and Will Dunham)