By Lawrence Hurley
WASHINGTON, April 27 (Reuters) - A day before the U.S. Supreme Court hears landmark arguments on whether the Constitution provides a right to same-sex marriage, activists on both sides of the contentious social issue converged on the white marble courthouse to voice their views.
Anti-gay rights activists rallied in front of the courthouse steps condemning same-sex marriage, while a line snaked around the block of people, many displaying gay rights messages, hoping to snag one of the limited number of seats available in the courtroom for Tuesday's 2-1/2 hour oral arguments.
The nine justices will be hearing arguments concerning gay marriage restrictions imposed in Kentucky, Michigan, Ohio and Tennessee, four of the 13 states that still outlaw such marriages. The ruling, due by the end of June, will determine whether same-sex marriage will be legal nationwide.
Before gay marriage became legal after a court ruling in the liberal northeastern state of Massachusetts in 2004, it was not permitted in any state. Now it is legal in 37 states and Washington, D.C.
Gay rights activists call same-sex marriage a leading American civil rights issue of this era.
At a small Monday morning rally, opponents of gay marriage, mainly representatives of Christian organizations, railed against judges who have struck down state gay marriage bans.
"Homosexuality is not a civil right," said one of the speakers, Greg Quinlan of the group New Jersey Family Policy Council.
Steven Hotze, a conservative Texas doctor, raised concerns about the impact legalized gay marriage would have on Christians who oppose it. "It would force individuals to have to condone, accept, even celebrate, sexual immorality," Hotze said.
Conservative Justice Anthony Kennedy may cast the deciding fifth vote on a court closely divided on gay rights. The four liberal justices are expected to support same-sex marriage, and Kennedy has a history of backing gay rights.
Tuesday's arguments will be divided into two parts. The first, set for 90 minutes, is on whether the Constitution's guarantees of due process and equal protection under the law mean states must allow gay couples to marry. The second, scheduled for an hour, concerns whether states must recognize same-sex marriages that take place out-of-state.
The legal repercussions for same-sex couples are broad, affecting not just their right to marry but also their right to be recognized as a spouse or parent on birth and death certificates and other legal papers.
Greg Bourke, one of the parties in the case from Kentucky, has been in a relationship with Michael De Leon since 1982 and they have two teenage children. In 2004, they were married in Canada, but because Kentucky does not recognize same-sex marriage Bourke is not legally recognized as a parent.
"For me, this lawsuit is about family," Bourke said. "What does it take to be recognized as a parent? I think I've earned it."
President Barack Obama is the first sitting president to support gay marriage. His administration will argue on the side of the same-sex marriage advocates. Nineteen states have filed court papers backing same-sex marriage. Seventeen are supporting the four states defending their bans.
Opinion polls show support among Americans for same-sex marriage has been rising in recent years.
Mary Bonauto, the lead lawyer arguing for gay marriage, said the case "doesn't rest on where public opinion stands." She also said people living in states where it is now legal have become comfortable with the idea of same-sex couples marrying.
Opponents say the legality of same-sex marriage should be decided by individual states, not judges. Some argue it is an affront to traditional marriage between a man and a woman and that the Bible condemns homosexuality. (Reporting by Lawrence Hurley; Editing by Will Dunham)