APEX - North Carolina's Democratic presidential primary is tightening, with Sen. Barack Obama's struggles in distancing himself from his controversial former pastor apparently eroding his once formidable lead.

The Tar Heel state was once seen as solidly in Obama's camp. But interviews with voters, politicos and experts, as well as three public opinion polls conducted in recent days, suggest that New York Sen. Hillary Rodham Clinton has been closing the gap.

Raleigh's Public Policy Polling has found that Obama's one-time lead of 25 points has decreased to 12. A SurveyUSA poll shows him ahead by 5, while the Rasmussen Reports poll has Obama's lead at 14.

Most of Obama's loss of support has been among white voters. Tom Jensen of Public Policy Polling attributes the drop to the Rev. Jeremiah Wright controversy, as well as campaign visits by Hillary and Bill Clinton in recent days. The surveys were taken before North Carolina Gov. Mike Easley endorsed Clinton and before Obama repudiated his former minister at a news conference Tuesday in Winston-Salem.

Kerry Haynie, a political scientist at Duke University, said Obama's support began to drop among working-class whites in earlier primary states such as Pennsylvania before the latest eruption of the Wright controversy.

"I think he has been damaged by all of this," said Haynie. "The flare-up exacerbated the trend already there. Democratic candidates who reach out to black voters tend to lose support among some white constituencies."

"It's a race-related explanation for that trend," Haynie said. "The more Obama becomes a black candidate or the candidate of blacks, the more support that we see falling off among some segments of the white population."

U.S. Rep. G.K Butterfield of Wilson, an Obama leader in North Carolina, said Obama has been hurt by the Wright controversy. But he also said it is natural that the primary is becoming more closely contested.

"That's typical in this kind of race," Butterfield said. "We didn't accept the double-digit lead of a couple of weeks ago. People are beginning to settle down and look at the race and make final choices."

"I think it will be a single-digit win," Butterfield said. "I believe Obama will win."

Ace Smith, Clinton's state director, said Clinton still faces an uphill race in North Carolina.

"The fact of the matter is, as recently as a week ago, he was up 25 points," Smith said. "Everyone would agree that the race is moving -- very good from our standpoint."

Even as North Carolina was becoming more competitive, Obama and Clinton were to campaign today in Indiana, which holds its primary on the same day as North Carolina's and which polls suggest is still the tighter of the two states.

On Tuesday, Obama called recent remarks by Wright "divisive and destructive" and said they don't reflect his views.

Wright said in recent days that the United States was attacked in 2001 because it engaged in terrorism and that the government used the AIDS virus to commit genocide against minorities. He also spoke favorably of Louis Farrakhan, the leader of the Nation of Islam.

Voters are leery

Interviews Wednesday with voters at Bill Clinton rallies in Apex and Sanford suggested that Obama has not put the Wright issue behind him.

Tony Perna said that there is no way he would vote for Obama and that if Obama is the Democratic nominee, he would back Republican Sen. John McCain. "He's been going to that church for a long time," said Perna, a 63-year old retired teacher from Holly Springs.

"Some of what he had to say is someplace in" Obama's mind, Perna said. "That is why I will never vote for Barack Obama."

"I think it's getting worse and worse for him," said Amy McCaskill, a 38-year-old Apex scientist and a Clinton supporter. She said Wright's rhetoric has gotten more absurd and damages Obama by association.

"He has real problems with working-class Democrats and whites," McCaskill added. "That is the base of the Democratic Party."

Penny Faulkner, a 58-year-old Apex nurse, said the Obama's denunciation is late and will be seen by many as a political move.

"He's been his spiritual adviser for 20 years," said Faulkner, a Clinton backer. "You can't decide that something is wrong or right depending on whether you are running for office."

Not everyone sees it that way.

J. Haydel, a 39-year-old Apex quality insurance engineer, thinks the Wright affair is a media creation.

"I don't know that it's had a big impact," said Haydel, an Obama supporter. "I didn't see it as a big thing to begin with."

Judy Walters, a 53-year-old teacher from Sanford who supports Clinton, said Obama should not be penalized for his minister's remarks.

"As a Christian you need to be accountable for yourself," Walters said. "People should not hold it against Obama because of what his preacher says."