NEW ORLEANS -- Three staunchly conservative Southern states were taking their last stands against same-sex marriage Friday before the U.S. Supreme Court is expected to settle the issue once and for all.
Louisiana went first, telling a federal appellate panel that giving gays and lesbians marriage rights is so risky and unproven that states must be allowed to protect their citizens against it.
Same-sex marriage is "a novel perception" in terms of recorded history, argued Louisiana's special counsel, Kyle Duncan.
Only ten years of data has been gathered since Massachusetts became the first U.S. state to legalize same-sex marriages, he said - not enough to know the consequences if courts keep overturning state-imposed bans.
"There are now 36 states and the District of Columbia that allow same-sex marriage and nothing has changed," countered Camilla Taylor, a Lambda Legal Defense Fund attorney representing seven couples challenging Louisiana's ban.
Duncan was frequently interrupted and challenged by judges Patrick Higginbotham and James Graves, who seemed more skeptical of the state's position than Judge Jerry Smith.
The three-judge panel of the 5th U.S. Circuit Court of Appeals also was hearing arguments for and against marriage bans in Texas and Mississippi. Higginbotham and Smith were appointed to the court by President Ronald Reagan; Graves was appointed by President Barack Obama.
The cases could be among the last to be heard in federal court before the nation's highest court decides the issue on its merits. The justices were meeting privately Friday to consider adding new cases to their late April argument session, and a decision could be announced soon.
With similar bans on gay and lesbian marriages being struck down around the nation, the appellate court in New Orleans took the highly unusual step of consolidating the three states' appeals into a single session.
U.S. District Judge Martin Feldman upheld Louisiana's ban, bucking a trend of 20 consecutive rulings overturning bans in other states. Feldman's ruling was the first to uphold a state ban since the Supreme Court struck down part of the federal Defense of Marriage Act in 2013.
Texas voters approved a constitutional amendment banning gay marriage in 2005; it was ruled unconstitutional last year, but remains in effect pending appeals. Mississippi has both a law and a constitutional amendment banning gay marriage, but its definition of marriage as only between a man and a woman was overturned after a legal challenge by two lesbian couples and a gay-rights group, Campaign for Southern Equality.
Anti-gay-marriage laws in Kentucky, Michigan, Ohio and Tennessee were upheld in November by the 6th U.S. Circuit Court of Appeals in Cincinnati. But four other appeals courts - based in Chicago, Denver, San Francisco and Richmond, Virginia - have ruled in favor of gay and lesbian couples. About 70 percent of the nation's population now lives in states where same-sex marriages are recognized.
The split among the appellate courts makes an eventual intervention by the Supreme Court very likely. Only 14 states still prohibit same-sex unions, which may give the justices reassurance that the country is ready for a nationwide change.
Three earlier seminal high court rulings that outlawed state-backed discrimination - involving education, interracial marriage and criminal prohibitions against gay sex - were issued when similar fractions of the country still kept discriminatory laws on their books.
Other states still enforcing same-sex marriage bans are Alabama, Arkansas, Georgia, Missouri (except in Kansas City and St. Louis), Nebraska, North Dakota and South Dakota.
A CBS News/New York Times poll taken last year showed more than half - 56 percent - of the country backs legalizing same-sex marriage.