Religion is supposed to be Barack Obama's strength.

Unlike many Democratic candidates before him, Obama speaks with ease about his faith. He attends Sunday worship and knows his Bible. His supporters believe he can pry some committed churchgoers away from the GOP.

But the furor over comments by his Chicago pastor, the Rev. Jeremiah Wright, broadcast again and again on TV and viewed by millions on YouTube, is tempering those hopes.

"It certainly gives people pause," even in the Democratic Party, said Corwin Smidt, a Calvin College professor who studies religion and politics.

All the top Democratic presidential contenders spoke of their faith this election year. Sen. Hillary Rodham Clinton, a Methodist and Obama's remaining Democratic rival, has spent years reaching out to traditional Christians. But more than any other candidate, Obama has made religion a core part of his message and outreach.

The Illinois senator has held faith forums, created a grass-roots support network of "congregation contacts" and has spoken at evangelical churches that Democrats had rarely visited.

His strategy is rooted in the Christian faith he found as an adult through Wright at Trinity United Church of Christ, a predominantly African-American megachurch. Obama's book, "The Audacity of Hope" was inspired by a Wright sermon.

But last week, Obama distanced himself from his pastor, after video circulated of Wright's most inflammatory rhetoric from the pulpit. Among the most remarked upon sound bites was Wright proclaiming "God damn America" for its racism. He also accused the government of flooding black neighborhoods with drugs. In a March 18 speech on race that was partly aimed at damage control, Obama described the history of injustice that fueled Wright's comments, while also condemning his pastor's statements and acknowledging the resentment of whites.

Shaun A. Casey, an Obama adviser and a Christian ethics professor at Wesley Theological Seminary in Washington, said the campaign will change nothing about its faith outreach because of the controversy.

"We're months and months away from the general election. I think that gives Senator Obama time to lay out his own views," Casey said. "Over time, people will spend a lot more time listening to what Senator Obama says than to a few well-chosen, cherry-picked video clips from his pastor."

But at least for now, the campaign is on the defensive.

No one expects Obama or Clinton to draw voters from the Christian right, especially considering the candidates' support for abortion rights.

Still, polls have found that younger evangelicals are less tied to the Republican Party than their parents have been. As a generation of old-guard Christian conservative leaders, such as the late Rev. Jerry Falwell, fade from the scene, some evangelicals are pushing for a broader agenda that includes environmental protection and fighting poverty. And Christian right activists remain wary of the presumptive Republican nominee, Sen. John McCain.

Democrats view this as a rare opening that could win them the White House. In a close general election, if the Democratic nominee can peel away even a small percentage of the traditional Christian vote, he or she could win the presidency.

Obama's focus on racial reconciliation has a special appeal to traditional Bible-believers. Their concern about diversity has intensified recently, in part because of the growth in immigrant churches in the U.S., and by a new awareness that conservative Christianity is spreading dramatically in developing countries. Multiethnic churches are a rarity in America.

The turmoil over Wright could cost Obama these votes.

Barry Hankins, a Baylor University historian who studies religion and politics, predicted that Christian right activists would bombard less-politically engaged evangelicals with the message that they should be leery of Obama because of his pastor.

"That's where it's going to hurt him," Hankins said.

James Guth, an expert on religion and politics at Furman University in South Carolina, said Wright's comments haven't killed Obama's chances. The candidate has built up some good will and "curiosity" through his outreach to evangelicals, including appearing at a Christian AIDS summit hosted by megachurch pastor Rick Warren and his wife, Kay.

But Guth said he had always been skeptical that Obama's strategy would succeed with traditional Christians. Wright's views inevitably would receive extensive publicity, as would Obama's denomination, the United Church of Christ, one of the most liberal of the mainline Protestant groups that theological conservatives deeply distrust, Guth said.

"I just thought the 'beginning of the end' would come during the general election, not the Democratic primaries," Guth said. "I don't think Obama has lost all the benefits of his earlier 'quiet' campaign among evangelicals, but this episode is certainly sets back those efforts."