(RNS) For the second time in less than a year, the Gallup poll reports that a majority of Americans would vote for an atheist for president.

The latest survey, from June, found that 54 percent of those asked said they would vote a "well- qualified" atheist into the Oval Office— the highest percentage since Gallup began asking the question in 1958, when only 18 percent said they would back a nonbeliever.

On the other hand, the survey showed that those who do not believe in God still come in behind every other group polled for, including gays and lesbians (68 percent) and Muslims (58 percent).

Still, an imaginary atheist candidate passed the 50 percent threshold for the first time when Gallup asked the question in August 2011, so the trend is upward.

"We have seen an enormous change over time in the willingness to vote for an atheist," said Karlyn Bowman, a senior fellow at the American Enterprise Institute for Public Policy Research, which reports the numbers in its current newsletter.

"But I think the numbers also remind us that this is a deeply religious country. That doesn't mean we are all going to church on Sunday, but that having religion in your life is valuable to most Americans and I think that explains the resistance."

Indeed, in the current poll, 43 percent said they would not vote for a well-qualified atheist, a percentage that was higher among Republicans than Democrats (58 percent) or independents (56 percent).

And there is more discouraging news for nonbelievers. In his analysis of the recent data, Gallup's managing editor Jeffrey M. Jones writes that for groups whose approval ratings hover within a narrow range of percentage points for more than 10 years — which might be happening for atheists — it can take more than fronting an appealing atheist candidate to reach more universal numbers, like those enjoyed by women (95 percent), blacks (96 percent) and Catholics (94 percent).

"It may be that there is an inherent bias that isn't going to change" for some groups, like atheists, whose numbers have leveled off, Jones said. "It is, in many cases, a long process and some of these groups have a way to go."

Herb Silverman, president of the Secular Coalition for America, knows that first-hand. In 1990, he ran for governor of South Carolina where an old law banned atheists like him from holding public office. Silverman lost — by a landslide — though his candidacy did lead to the repeal of the law by the state's supreme court.

Silverman, who tells the story of his run for office in his book "Candidate Without a Prayer," says that to push their approval numbers higher, more atheists need to "come out," just as gays and lesbians have done.

"I think prejudices will always be with us, so I am not optimistic enough to think (atheists' approval rating) will be near unanimous," he said. "But I think the more role models we have the better things will be."

Tom Flynn, editor of Free Inquiry magazine, an atheist publication, agrees.

"When you think you don't know any atheists then they seem horrible, but when the person at the desk across from you is an atheist then those stereotypes don't hold," Flynn said.

But he's a glass-is-half-empty guy, too.

"We have to keep in mind that we atheists are still the group that the smallest number would vote for," he said. "We are riding that train into the sunlight of equality, but we are still sitting in the caboose."