A liberal political group that is leading the charge against President Bush’s re-election, MoveOn.org, came under fire yesterday from religious organizations and individuals who said a newspaper advertisement the organization took out demonstrated bias against evangelical Christians.

The full-page ad, which appeared in yesterday’s New York Times, challenged the polling techniques used by one of the nation’s preeminent polling firms, the Gallup Organization. The ad said that other polls showed the Bush-Kerry race as neck-and-neck, but Gallup ascribed a substantial lead to the incumbent. Poll results, the ad said, influence coverage of the campaign and “the public’s perceptions of the candidates.”

The MoveOn.org ad also suggested that the religious beliefs of Gallup’s former co-chairman, George Gallup Jr., have skewed the firm’s numbers. The company founded by Mr. Gallup’s father in 1935 was acquired by Nebraska based SRI Inc. in 1988. Mr. Gallup, though he remained an executive of the Gallup Organization until recently, said he now has nothing to do with its presidential polling.

“Why hasn’t he pushed for an update of the company’s likely voter modeling, which his own father pioneered in the 1950s?” the MoveOn.org ad asked. The political group then appeared to answer its own question.

“Gallup, who is a devout evangelical Christian, has been quoted as calling his polling ‘a kind of ministry.’ And a few months ago, he said ‘the most profound purpose of polls is to see how people are responding to God,'” MoveOn said. “We thought the purpose is to faithfully and factually report public opinion.”

A former mayor of Boston, Raymond Flynn, said he was disturbed by the ad’s discussion of Mr. Gallup’s religious views.

“I was deeply concerned when I read it,” Mr. Flynn said. “There’s a growing, blatant, anti-religious sentiment in the United States. It’s oftentimes well camouflaged and very subtle. It’s very troubling and disturbing.”

Mr. Flynn, a Democrat who is a Catholic and served as ambassador to the Vatican under President Clinton, has spoken out against what he perceives to be bias against those who have strongly held religious beliefs. The former mayor said he was particularly offended by the suggestion that Mr. Gallup’s political beliefs could be inferred from his religious views.

“You’re affecting the Gallup Organization’s reputation. You’re slandering this reputable, respected business,” Mr. Flynn said. “At some point in time, there has to be some level of decency that someone stands up and says, ‘No.'”

The national director of the Anti- Defamation League, Abraham Foxman, also decried the religious references in the MoveOn.org ad.

“It’s irrelevant, extraneous, and borders on being offensive to evangelical Christians,” Mr. Foxman told The New York Sun. “It’s one thing to challenge methodology and credibility. It’s another thing to say that the methodology and credibility are motivated by faith. … What if the poll was headed by a devout Jew? How would we have felt?”

A spokesman for MoveOn.org, Trevor Fitzgibbon, had no response yesterday to the criticism of the group.

In an interview with the Sun, Mr. Gallup, 74, said he was taking the assault on his work in stride.

“I wasn’t angered,” Mr. Gallup said. “I’ve been polling for 50 years. Particularly at election time, people get very uptight and start throwing brickbats.”

Mr. Gallup dismissed the notion that he had skewed polls to produce any particular result.

“One, it’s dishonest. Two, that would be absurd, it would make you look terrible, for the company and everything,” he said. “That’s off the wall, totally off the wall.”

Mr. Gallup noted that he retired from the polling concern June 1. “I’m involved in very little at this point,” he said.

The veteran pollster said he did see some of the ad’s language as a critique of his religious views. “Evangelical – it’s sort of used in a pejorative way,” he said.

Mr. Gallup also said he saw no reason why he should be singled out simply because he has expressed his religious faith in public. “Every person in the polling field has a faith of some sort or other or a faith in someone or other,” he said. “Having no faith is a form of faith.”

The Bush and Kerry campaigns did not return calls seeking comment on the ad.

In the ad, MoveOn.org asserted that Gallup weights its polls of likely voters in favor of Republicans. The liberal group said that while Gallup’s system suggests that GOP turnout will exceed Democratic turnout by 6 to 8 percentage points, in recent elections self-declared Democrats have gone to the polls in greater numbers than did Republicans. MoveOn.org said Gallup’s screening process for likely voters could explain the results of an eye-catching poll that the firm released last week showing Mr. Bush leading Senator Kerry of Massachusetts by 55% to 42%.

Without elaboration, the ad also said the Gallup Organization has been asked to select the audience for the October 9 presidential debate, which is to have a “town meeting” format.

Other pollsters interviewed for this story said they considered Gallup’s 55-42 result to be an outlier, or a fluke. They said, however, that they saw no reason to believe Gallup was deliberately tilting its polls toward Republicans.

“There’s nothing in it for any of us not to get right what happens on Election Day,” said the president of the American Association for Public Opinion Research, Nancy Belden. “We have every motivation to get it right, not to send a message.”

In Gallup’s most recent poll, released Monday, Mr. Bush was just 8 percentage points ahead among “likely voters.”

The director of the Marist Poll, Lee Miringoff, noted that in the most recent Gallup survey Mr. Bush actually held a bigger lead, of 11 points, among registered voters. Thus, in the new poll the firm’s screen for likely voters moved the results in Mr. Kerry’s favor.

“It pulled it the other way,” Mr. Miringoff said.

In 2000,Gallup’s final survey predicted that Mr. Bush would get 48% of the vote and Vice President Gore would get 46%. Both men got 48%. Gallup’s accuracy was slightly better than the average for major polls.

In a written statement yesterday, Gallup said it “scrupulously adheres to a set of neutral principles in polling to make sure that we are at all times unbiased and scientifically objective in all that we do.” The organization said that its methodology on likely voters has proven accurate for decades and that any deviation has been as likely to favor the Democrats as the Republicans.

Conservative religious groups said the Times ad showed an obvious anti-Christian bias on the part of MoveOn.org.

“Clearly, MoveOn.org has a very anti-Christian bent,” said a spokeswoman for the Tradition Values Coalition, Andrea Rafferty. “We’re constantly seeing it be open season on people of faith.”

“This is part of a whole effort to force people from public confessions of faith,” said the president of the Family Research Council, Tony Perkins. “It just shows the hostility that some radical elements have towards Christianity.”

For his part, Mr. Gallup said the criticism he received will not shake his conviction that pollsters should inquire about religious issues and faith. “If you’re truly earnest about seeking where people are, not only in their minds but in their hearts and souls, you have to ask those questions,” he said.

Mr. Gallup speaks regularly to religious organizations and groups. One quote came from remarks he made to the First Church of Christ, Scientist in Boston in 1998.

During that session, he said, “I do believe my work is a kind of ministry, because the most worthy pursuit and profound purpose of surveys is to determine to the extent it’s possible how people are responding to God.”

Another remark came from a press conference Mr. Gallup held in May after speaking at his daughter’s graduation from a Massachusetts divinity school, the Gordon-Conwell Theological Seminary. The Gallup organization said his remarks there had been taken “completely out of context.”

A report by the Religion News Service on Mr. Gallup’s remarks at the seminary indicates that he was referring there to his religious surveys.

“When I ask a question on these subjects, what I’m always trying to find out is, ‘are we doing the will of God?”‘ Mr. Gallup was quoted as saying.