In 1996, the US Congress passed the Defense of Marriage Act signed into law by President Bill Clinton.

It states that "the word 'marriage' means only a legal union between one man and woman as husband and wife." And 36 states have passed similar laws.

All could be tossed into the ashcan of history - along with a 1986 opinion of the Supreme Court which upheld a Georgia sodomy statute. Chief Justice Warren E. Burger wrote that to overturn the law would "cast aside millennia of moral teaching" to say sex between gay men is "is somehow protected as a fundamental right."

Only 17 years later, the court is being asked to overturn a similar Texas law and label Burger's view as bigoted and archaic. "There is no legitimate, rational reason for only same-sex couples to be treated as second-class citizens," argued Washington lawyer Paul Smith this week.

Chief Justice William Rehnquist demurred that differences between heterosexuality and homosexuality had been "recognised for a long time." Indeed, as recently as 1960 all 50 states had laws against sodomy, some of which are as old as the nation. However "three-fourths of states (currently) don't regulate this conduct for anyone," Smith asserted.

He noted that the Texas law that prohibits "deviate sexual intercourse, namely anal sex" but "only for same-sex couples." It does not apply to the same sexual act by heterosexuals. That violates 14th Amendment's guarantee of equal protection under the law because "it is directed not just at conduct but at a particular group of people - same-sex couples," Smith said in defending two Texas men who were discovered by police having anal intercourse in a Houston apartment.

He also asserted there was an invasion of privacy, though the police were investigating a false report of a disturbance involving a gun, when they entered John Lawrence's apartment where he was having sex with Tyron Garner. Both were fined $200.

Harris County, Texas District Attorney Charles Rosenthal argued that the Lone Star State's ban "does not violate the 14th Amendment... because the Constitution has never recognised a fundamental right to engage in extramarital sex."

America has a long tradition of regulating sexual conduct outside of marriage. And Texas "has a right to set moral standards and can set bright line moral standards for its people." In emphasising the right of states to pass laws that uphold marriage by frowning on extra- marital conduct, he noted the Supreme Court settled the matter in its 1986 decision in the Georgia case.

Smith constantly reinforced his arguments that the case went beyond the equal protection clause to involve a fundamental right of ALL adults to engage in sex in private. Justice Antonin Scalia fired back, asking Smith, "Aren't there statutes on adultery? Are they unconstitutional? What about rape laws that only apply to male-female rape? Do you think they are unconstitutional? Why is this different from bigamy?"

Although Scripture was not quoted, what came to my mind was Hebrews 13:4: "Honour marriage, and guard the sacredness of sexual intimacy between wife and husband. God draws a firm line against casual and illicit sex." (The Message) However, more justices appeared sympathetic to gays challenging the Texas law.

When Rosenthal emphasised "the rights of states to determine their own destiny," Justice Stephen Breyer said it appeared that Texas was claiming the right to ban private sexual behavior simply because it did not like it. Rosenthal retorted that if a change in law is needed, "it belongs in the Statehouse of Texas, not this court," with an impetus from "the people of Texas" who decided that the "line should be drawn at the door of the marital bedroom."

Breyer snapped, "This case is in the bedroom."

Justice David Souter asked Rosenthal: "What harm does the law prevent?" Oddly, he did not reply that anal sex is the way 150,000 American men contracted AIDS.

An "amicus" brief of the Family Research Council quoted historians Will and Ariel Durant: "Sex is a river of fire that must be banked and cooled by a hundred restraints if it is not to consume in chaos both the individual and the group."

Laws that approve of sex only within marriage elevate that relationship. It has "as noble a purpose as any involved any involved in our prior decisions," the Supreme Court stated in a 1965 case.

Congress, in supporting of the Defense of Marriage Act, wrote: "Why is marriage the most universal social institution, found prominently in virtually every known society? Much of the answer lies in the irreplaceable role that marriage plays in childrearing and in generating continuity."