The votes, too, are going differently these days. Ballot measures, state legislatures, and Supreme Court decisions testify to a new public consensus on gay marriage, the political issue that currently serves as the chief proxy for attitudes toward gay rights and acceptance.

Gradually, and largely below the radar, religious Americans have powered this momentous shift. In 2004, just 36 percent of Catholics, the Christian sect most supportive of gay marriage, favored it, along with 34 percent of mainline Protestants; today, it's 57 percent of Catholics and 55 percent of mainline Protestants. Even among white evangelical Protestants, the most hostile group to gay marriage, support has more than doubled, from 11 percent in 2004 to 24 percent in 2013. "This debate has gone from a debate between nonreligious and religious Americans to a debate dividing religious Americans," said Robert Jones, CEO of the Public Religion Research Institute, who has closely tracked the evolution in public opinion.

This change -- from most religious Americans opposing gay rights to many of them supporting it -- didn't happen by accident. It is the fruit of an aggressive campaign by a determined gay-rights movement that realized, particularly in the wake of the 2004 elections, that you cannot win politically in America if you are arguing against religious faith. It is a recent development -- Jones dates the "tipping point" to 2011 -- and it has helped marginalize gay-marriage opponents by discrediting their most powerful claim: that they speak for the religious community.

For gay Americans, the consequences are already profound: a new generation of gay youth that may grow up less scarred by caustic preaching. The political repercussions, still unfolding, hold the key to further progress in the fight to expand gay rights, particularly marriage, nationwide.

"After the 2004 elections, the story was that we were losing to the value voters," said Sharon Groves, director of the religion and faith program of the Human Rights Campaign -- a position created in 2005. "Family values were defined, largely, as anti-LGBT. The people making the case for the family values side were religious leaders, and we as a movement were responding with advocates and lawyers." The message audiences got from that image: Religion was on one side and gay rights was on the other.

Groves spent last weekend manning a booth for her organization at the Wild Goose Festival, an annual gathering of social-justice-minded Protestants in rural North Carolina sometimes dubbed "Woodstock for Evangelicals." It was the first time the Human Rights Campaign had a formal presence at the festival. Over and over, people came to her tent, burst into tears, and said, "I'm so happy you're here."

"I get it all the time," she said. "People have been told for so many years if you're a gay person you basically don't belong in the religious community. And straight folks, too, want to see their religion as a source of love and inclusion that's making people's lives better, not shaming people or keeping them out."