If the Court does, it would overturn a widely criticized ruling 17 years ago reports CBS News Correspondent Christopher Glenn.
The court appeared deeply divided over a Texas law that makes it a crime for gay couples to engage in sex acts that are legal for heterosexual couples.
States should not be able to single out one group and make their conduct illegal solely because the state dislikes that conduct, lawyer Paul Smith argued for the Texas men.
"There is a long history of the state making moral judgments," retorted Justice Antonin Scalia. "You can make it sound very puritanical," but the state may have good reasons, Scalia added.
"Almost all laws are based on disapproval of some people or conduct. That's why people regulate," Chief Justice William H. Rehnquist added dryly.
Justice Stephen Breyer challenged Houston prosecutor Charles Rosenthal to justify why the state has any interest in peeping into the bedrooms of gay people.
"Why isn't that something the state has no business in, because it isn't hurting anybody?" Breyer asked.
The state has an interest in protecting marriage and family and promoting the birth of children, Rosenthal replied. "Texas can set bright line moral standards for its people."
A large crowd stood in line outside the court before the oral arguments in hopes of getting a scarce seat for one of the court's biggest cases this year. A knot of protesters stood apart, holding signs that read "AIDS is God's revenge," "God sent the sniper" and other messages.
State anti-sodomy laws, once universal, now are rare. Those on the books are infrequently enforced but underpin other kinds of discrimination, lawyers and gay rights supporters said.
"We truly hope the Supreme Court in its wisdom will remove this mechanism that has been used for so long to obstruct basic civility to gay and lesbian people," said Elizabeth Birch, executive director of the gay rights organization Human Rights Campaign.
In 1986, a narrow majority of the court upheld Georgia's sodomy law in a ruling that became a touchstone for the growing gay rights movement. Even then the court's decision seemed out of step and was publicly unpopular, said Harvard law professor Laurence Tribe, who argued on the losing side of the case.
"We're now dealing with a very small handful of statutes in a circumstance where the country, whatever its attitudes toward discrimination based on sexual orientation, (has reached) a broad consensus that what happens in the privacy of the bedroom between consenting adults is simply none of the state's business."
As recently as 1960, every state had a sodomy law. In 37 states, the statutes have been repealed by lawmakers or blocked by state courts.
Of the 13 states with sodomy laws, four - Texas, Kansas, Oklahoma and Missouri - prohibit "deviate sexual intercourse," or oral and anal sex, between same-sex couples. The other nine ban consensual sodomy for everyone: Alabama, Florida, Idaho, Louisiana, Mississippi, North Carolina, South Carolina, Utah and Virginia.
An unusual array of organizations is backing the two Texas men. In addition to a long list of gay rights, human rights and medical groups, a group of conservative Republicans and the libertarian Cato Institute and Institute for Justice argued in friend of the court filings that government should stay out of the bedroom.
"This case is an opportunity to confirm that the constitutional command of equal protection requires that gays be treated as equal to all other citizens under the law, subject to neither special preferences nor special disabilities," the brief for the Republican Unity Coalition said.
On the other side, the Texas government and its allies say the case is about the right of states to enforce the moral standards of their communities.
"The states of the union have historically prohibited a wide variety of extramarital sexual conduct," Texas authorities argued in legal papers. Nothing in that legal tradition recognizes "a constitutionally protected liberty interest in engaging in any form of sexual conduct with whomever one chooses," the state argued.
Conservative legal and social organizations, religious groups and the states of Alabama, South Carolina and Utah back Texas in the case.
The case began in 1998, when a neighbor tricked police with a false report of a black man "going crazy" in John Geddes Lawrence's apartment. Police pushed their way in and found Lawrence having anal sex with another man, Tyron Garner.
Although Texas rarely enforced its anti-sodomy law, officers decided to book the two men and jail them overnight on charges of "deviate sexual intercourse with another individual of the same sex." They were each fined $200 plus court costs.
Also on Wednesday, in a case that could affect the visitation rights of millions of prisoners, the justices struggled with the question of whether inmates have a constitutional right to visits with friends and family.
Specifically, the question before the high court was whether Michigan violated that right when it imposed a restrictive visitation policy.
Michigan put into effect stricter rules in 1995 to better protect visitors and to stop the smuggling of drugs and weapons. Minors who weren't an inmate's child or grandchild were no longer allowed to visit. Nor were former prisoners, unless they were immediate family. Inmates with two substance abuse violations in prison could have visitation privileges taken away altogether.
Deborah LaBelle, an attorney for Michigan prisoners, said the rules violated a constitutional right to intimate association by categorizing the people that inmates could have contact with.
And the Court narrowly upheld a practice used in every state to raise money for legal services for the poor.
The court's 5-4 decision was a huge relief to advocates for the poor. A ruling the other way would have wiped out about $200 million generated each year for lawyers who represent the indigent.
The money comes from short-term interest earned on escrow accounts that lawyers set up to handle clients' real estate transactions and other deals.
Lawyers maintain that it's cheaper and easier to combine money into large trust accounts than to set up individual accounts for each client. And they say the interest goes to a good cause.
It was challenged as an unconstitutional taking in violation of the Fifth Amendment, which says property shall not be taken for public use without fair compensation.