After a federal appeals court on Monday struck down a gay marriage ban passed by 57 percent of voters in Virginia, Roy Cooper, attorney general for Virginia’s neighbor, North Carolina, hoisted a surrender flag.

“There’s no argument left” against banning two consenting adults of the same sex from getting hitched, he said. Mr. Cooper, a Democrat, announced that he will no longer defend the state's gay-marriage ban in court.

The Monday ruling by a three-judge panel of the Fourth Circuit Court of Appeals in Richmond, Va., binds federal judges throughout its entire jurisdiction, which includes Bible Belt states such as Virginia, North Carolina, and South Carolina. The ruling will not legally take effect for another three weeks, during which time the defendants can appeal and demand a stay of the order.

The 2-to-1 decision is important on several levels, with the court supporting a fundamental constitutional right for gays to marry and the ruling coming in a state where half a century ago – in Loving v. Virginia – the US Supreme Court said that government can’t keep white and black people from marrying. Moreover, it adds to the likelihood that the Supreme Court will at some point take up the issue.

But the Fourth Circuit’s ruling also comes at a time when the cultural and political battle over gay rights is in full swing throughout the South.

The conflict between post-Civil War “equal rights” amendments to the Constitution can still chafe against the precepts, and argued primacy, of certain interpretations of the Bible in the South. In this case, Bible passages say homosexuality is sinful, but the 14th Amendment to the Constitution says the federal government can uphold basic individual rights, even against the wishes of a majority.

These two forces are openly clashing. Earlier this year, for example, Georgia briefly considered mimicking a failed Arizona bill that would’ve allowed religious business owners to discriminate against gay people by refusing service. But the bill was quickly squashed by establishment Republicans, who saw the possible backlash and boycotts from such a “Christian shield” law as far worse than any potential gains.

Yet, at the same time, the legal and cultural foundations for gay marriage bans in the South are being shaken.

Mississippi, where gay marriage is illegal, has the highest percentage of gay couples raising children, according to a report by the Williams Center at the University of California at Los Angeles, which studies gender identity law and policy. And Mississippi is not an outlier: Socially conservative states, many in the South, have higher rates of gay couples raising kids, the Williams Center found. Virginia has 2,500 gay couples raising some 4,000 children.

Different studies have also found that Southern gays are not cloistered only in Atlanta neighborhoods like Midtown and Buckhead. One in 10 couples in rural and mountainous Fannin County, Ga., is gay, according to 2010 census figures. And acceptance is quickly spreading. Today, half of Southerners support gay marriage, a March Washington Post/ABC News poll found.

And this spring, following a district court ruling, Arkansas began allowing gay marriage. The state issued marriage certificates to more than 450 gay couples from May 9 to 16, when the state Supreme Court stayed the ruling. Still, those certificates were the first such documents ever to be signed in the Bible Belt.

In gay-friendly Blue Ridge, Ga., a Methodist minister named Doug Burrell summed up the mood in the South: “[A] lot of older folk here … struggle to adapt to new realities,” Mr. Burrell told the Guardian, a British newspaper. “And you know, this is the South. We’re polite to people but it doesn’t mean we like them.”

The practical effects of Monday’s ruling and Cooper’s decision to stop defending North Carolina's anti-gay marriage law won’t be known for a while. The US Supreme Court could take up the Fourth Circuit decision, and the North Carolina governor (a Republican) could take up the defense of the state ban on gay marriage.

Currently, 19 states and the District of Columbia recognize same-sex marriages, while 31 states have statutes or constitutional amendments that bar same-sex marriage. So far, 19 lower court judges at both the federal and state level have struck down marriage bans.

Legal analysts contend that what made the Virginia ruling significant is that it was the first in a class-action suit, it leaned heavily on how states’ rights intersect, and touched on tradition versus equal rights. Judge Henry Floyd, writing for the majority, called the ban “precisely the type of segregation that the Fourteenth Amendment cannot countenance.” The 14th Amendment guarantees all US residents equal protection under the law.

In a dissent, Judge Paul Niemeyer argued that for a gay marriage right to exist it has to have been rooted firmly in tradition, causing him to worry that a fundamental right to marriage could go awry – including giving the right “of a father to marry his daughter or the ‘right’ of any person to marry multiple partners.”

[Editor's note: The original version incorrectly identified some of the states in the Fourth Circuit Court of Appeals. It also did not make clear the period during which Arkansas issued marriage certificates to gay couples.]