EDEN, N.C. » John G. Kallam Jr., 67, carries a worn black Bible and another copy on his iPad, and believes Scripture is unequivocal.

"Sodom and Gomorrah, that story alone tells you what God thinks of same-sex marriage," he said. "God said that homosexual behavior is a sin and that marriage is between a man and a woman."

Like three-quarters of the voters in rural Rockingham County, he checked "yes" in the 2012 plebiscite when North Carolina joined some 30 other states in adopting constitutional bans on same-sex marriage. "I breathed a sigh of relief," he recalled. "I thought that was the end of it."

But last October, Kallam, like many other conservatives across North Carolina, was stunned when, two years after "the people spoke," as he put it, a federal judge overturned the ban.

An appointed county magistrate, Kallam was obligated to perform civil marriages whether they were same-sex or not. So he resigned, one of six in the state who stepped down to avoid violating their faith.

As the Supreme Court prepares to hear arguments on same-sex marriage next Tuesday, the nation seems more ready to accept it than many imagined even a year ago. But divisions remain, and while more than half of Americans now endorse the idea, about one-third say they oppose it, according to survey data from 2014.

In Northeastern states like Vermont and New York, large majorities support same-sex marriage. And in many more states including California, where a vote in 2008 to ban it was later overturned by the courts, such marriages have become routine.

In perhaps a dozen other states, mainly in the South and the Great Plains, majorities still think that gay and lesbian couples should not be allowed to marry, studies indicate. Some conservative leaders promise to keep defending that view whatever the Supreme Court decrees — and even if they have few practical options.

"If the government wants to pretend to redefine marriage, I don’t think that will settle the issue," said Tami Fitzgerald, the executive director of the North Carolina Values Coalition.

Still, once the Supreme Court speaks, in a decision widely expected to make same-sex marriage a national right, the opponents’ anger and energies are likely to focus on a more limited issue, what they call protections for conservative religious officials or vendors who want to avoid involvement in same-sex weddings.

Gerald N. Rosenberg, a political scientist and legal scholar at the University of Chicago, said his former predictions of a wider, lasting backlash to marriage rulings have been overtaken by the "sea change in public opinion."

Such "opt out" proposals may produce political heat, as recently seen in Indiana and Arkansas, where the governors, under pressure from businesses, felt compelled to weaken so-called religious freedom bills. But they will not impede the ability of gay and lesbian couples to marry, Rosenberg said.

In North Carolina, the Senate president, Phil Berger, a Republican from Rockingham County, is the chief sponsor of a bill that would allow the county officials who issue marriage licenses as well as magistrates to decline to participate in marriages on religious grounds. The bill has passed the Senate.

It is strongly opposed by gay rights advocates who argue that "public officials can’t pick and choose," in the words of Chris Sgro, the executive director of Equality North Carolina.

The strongest resistance so far to court-directed change has been in Alabama, where the state Supreme Court ruled that a federal judge’s decision striking down the gay marriage ban should apply only to the specific plaintiffs. In legal limbo, the state is waiting to see how the Supreme Court will decide.

Yet whatever resistance strategies are adopted, many legal and political experts who have studied the impact of divisive Supreme Court rulings in the past, and the trajectory of the gay marriage movement, say they do not expect a lasting, powerful backlash of the kind that followed decisions on school desegregation and abortion.

Instead, the experience in states where same-sex marriage has already been legalized suggests that public opposition is likely to wither over time.

"As more couples marry, more people will know people who are married," said Michael J. Klarman, a legal historian at the Harvard Law School and author of a 2012 book on earlier gay marriage rulings. "And those who oppose it will find out that the sky doesn’t fall."

Without question, the legal turn has been abrupt. Since mid-2013, when the Supreme Court invalidated the part of the Defense of Marriage Act that forbade the federal government to recognize same-sex marriages, the number of states in which same-sex marriage is permitted jumped from around a dozen to 37, if Alabama is included, and the District of Columbia.

Most of these states were required to change by federal courts, often provoking the resentments expressed by Kallam, especially in rural regions. If the Supreme Court extends marriage rights, all remaining states will be forced to end restrictions.

As fast as the law has moved, public support for same-sex marriage has also accelerated in recent years, even in the lagging states, rising to 56 percent nationally in 2014, from 30 percent in 2004, according to the General Social Survey.

Also significant is the large gap in attitudes between young and old. In contrast to abortion, about which opinions have varied little for decades, "those who oppose gay marriage are slowly aging out of the electorate," said Patrick J. Egan, a political scientist at New York University.

The earliest state court decisions favoring same-sex marriage — in Hawaii in 1993 and Massachusetts in 2003 — did provoke strong reactions, helping lead to the 1994 federal marriage law and a later profusion of restrictive state amendments.

The opponents registered an unbroken string of ballot victories right up to the one here in North Carolina in May 2012. But later that year, the other side started to win elections.

"The winds have shifted dramatically and the first wave of backlash, which was overwhelming, will not be repeated," said Jane S. Schacter, a professor of constitutional law at Stanford Law School.

In North Carolina, the divisions and shifts in attitudes were apparent in recent conversations in Greensboro and nearby Rockingham County, where the pale green of spring was streaked with dogwood blossoms and empty textile factories are a reminder of more prosperous days.

In Greensboro, a city of 280,000 and the seat of Guilford County, Jeff L. Thigpen is the elected register of deeds, whose office issues marriage licenses. He describes himself as a Christian "who began to see that my faith is not an impediment to loving my neighbor."

One tangible change since October is on the office computer that couples use to fill out marriage license applications. Formerly, when the applicant typed in his or her gender, the screen’s background turned blue or pink. Now, it is a uniform gray-blue for all. By mid-April, the county had issued more than 300 same-sex licenses, Thigpen said.

Thirty-five miles north, in Eden, population 15,000, the Rev. Steve Griffith is the senior pastor of the church Kallam attends, the Osborne Baptist Church. Located in a onetime headquarters of Fieldcrest Cannon, the defunct textile giant, the church attracts some 1,500 worshippers on Sunday.

Griffith, 52, who is apt to wear T-shirts and jeans even at services, firmly believes that homosexual behavior is a sin, but he senses the political trends.

"I fully expect that same-sex marriage will become the law of the land," he said. But he does not intend to perform such marriages.

Still, many churchgoing residents here viewed the issue with a live-and-let-live shrug.

"I’m not in favor of gay marriage, it’s a sin, but there’s not much I can do about it," said Sandra Vernon, 64, a retired office worker, as she left a coffee shop in nearby Reidsville.

The flux in opinions was expressed by Kristina Bailey, 27, who is studying for teaching credentials at Rockingham Community College. She is an active church member, and she voted in 2012 for the amendment to outlaw gay marriage.

But her views have softened, in part because of a chance encounter at a pet supply store. Now, she says, she has mixed emotions about the issue.

Her 5-year-old daughter had acquired a hermit crab at the beach, and they went to the store to buy a habitat for it. There they met and became friends with the saleswoman, who married her longtime female partner in October.

"I was happy for them at a personal level," Bailey said.

"I don’t want to force my religious views on someone else," she said. "If they can prevent people from marrying who they want, they can keep me from going to the church I want."

The saleswoman, Ann Marie Jarvis, and her wife, Christy Michelle Finney, had been together for 17 years when marriage became possible last fall.

The couple have chosen to stay in Reidsville, where they have supportive relatives and a supportive pastor, Jarvis said in an email.

"People in this small community have been very welcoming," she said.

Erik Eckholm, New York Times

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