Over the last decade, though, the debate has shifted from one between religious and non-religious Americans to one that primarily pits older, conservative Christians against moderate, progressive, or younger Christians, Jews, and the religiously unaffiliated.
Today, there are religious groups on both sides of the same-sex marriage debate. Public Religion Research Institute’s American Values Atlas—based on 40,000 interviews—shows some striking realignments over the last decade. A number of major religious groups have joined the unaffiliated in supporting same-sex marriage. In addition to the more than three-quarters of the religiously unaffiliated who support same-sex marriage, 84 percent of Buddhists, 77 percent of Jews, approximately six in ten white mainline Protestants (62 percent), white Catholics (61 percent) and Hispanic Catholics (60 percent), and 56 percent of Eastern Orthodox Christians now support allowing gay and lesbian couples to marry legally.
On the other side of the debate, 68 percent of Jehovah’s Witnesses, 66 percent of Mormons and white evangelical Protestants, and more than half of Hispanic and black Protestants oppose same-sex marriage.
These reconfigured battle lines are also evident in the dueling friend-of-the-court briefs filed by two different groups of religious organizations—one urging the court to overturn bans on same-sex marriage and one arguing to uphold them.
Conceding the loss of some religious groups in their ranks, many conservative religious leaders nonetheless continue to assert that religious Americans overall continue to oppose same-sex marriage. Even among religiously affiliated Americans, however, supporters today actually slightly outnumber opponents. Among all religiously affiliated Americans, 47 percent favor allowing gay and lesbian couples to marry, compared to 45 percent who oppose. (The survey’s huge sample-size makes even this narrow margin statistically significant.)
This new terrain is not only lost on conservative religious leaders; opponents of same-sex marriage, more than other Americans, remain convinced that public opinion is on their side. In early 2014—more than a year after national polls began consistently finding majority support for same-sex marriage—Americans who opposed legalizing same-sex marriage were roughly three times more likely to say that most of the country opposed rather than supported same-sex marriage.
Because support for same-sex marriage is higher among religiously unaffiliated Americans, many wrongly believe that the movement of non-religious Americans are primarily responsible for the new battle lines. But in fact, the bulk of the shift in favor of same-sex marriage over the past decade has taken place among religious Americans. While more than three-quarters of religiously unaffiliated Americans favor same-sex marriage today, that number is up only 12 percentage points since 2003.