With the exception of white evangelical Protestants, majorities of major religious groups — including Roman Catholics — favor legalized abortion, according to the survey. Only 29 percent of white evangelicals said abortion should be legal in most or all cases.
The findings reflect a "decoupling" of the debates over abortion and same-sex marriage, according to Jones, who predicted the two issues "will increasingly go forward on their own tracks."
He noted that focus groups of millennials convened as part of the survey tended to depict same-sex marriage — but not abortion — in positive terms.
"Abortion is just a different kind of issue, even for those who support it," Jones said. "It's not the kind of issue that one celebrates."
The findings mesh with recent commentary by some conservative leaders, who feel they can compete vigorously for the backing of young people on abortion issues but acknowledge setbacks in opposing same-sex marriage.
"We're losing on that one, especially among the 20- and 30-somethings," said Jim Daly, president of Focus on the Family, in a recent interview with World Magazine. "I don't know if that's going to change with a little more age — demographers would say probably not."
Leslie Kantor, national director of education for the Planned Parenthood Federation of America, said the surge of young adults' support for same-sex marriage could be explained by the fast pace of gay-rights political change and by the prevalence of gay characters and celebrities on TV and in other media.
"For young adults, the vast majority know someone in their life who is gay," Kantor said. "There's no comparable coming out process related to abortion — even though by age 45 one-third of American women will have had one."
Angela Ferrell-Zabala, who does abortion-rights outreach on college campuses for the Religious Coalition for Reproductive Choice, said young adults' attitudes may be affected somewhat by campaigns depicting abortion as shameful.
But as many legislatures toughen state restrictions on abortion, she contends there are signs of an abortion-rights backlash.
"I'm seeing young people reaching out, who are outraged by these attacks," she said.
At a news conference Thursday, discussing the survey, Jones said he was struck by the "MTV effect" that it revealed.
According to the survey, respondents who had seen MTV's popular reality shows about teen pregnancy — "16 and Pregnant" or "Teen Mom" — were significantly more likely than the general public to say abortion is morally acceptable and should be legal in most or all cases.
The survey was based on telephone interviews conducted between April 22 and May 8 among a random sample of 3,000 adults in the continental United States, including 750 who were interviewed on cell phones. The margin of error for the full sample is plus or minus 2 percentage points, and higher for subgroups.
Public Religion Research Institute: http://www.publicreligion.org/
David Crary can be reached at http://twitter.com/CraryAP
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