RALEIGH - Sen. Barack Obama entered the presidential battle a year ago as the byproduct of dual worlds, someone who captured idealists by saying Americans can push beyond the barriers that have haunted humanity for generations. He wanted to be the candidate beyond race.

Yet two days before crucial primaries in North Carolina and Indiana, those very divisions now threaten to overshadow the battle between Obama and Sen. Hillary Rodham Clinton for the Democratic nomination.

Here in the Tar Heel state, where issues involving race helped sink the prospects of candidates from Terry Sanford to Harvey Gantt, some white Democrats tell pollsters they still feel less comfortable putting a black person in the White House, and Obama gets huge support from blacks. In the past week, amid a new flare-up involving Obama's former pastor, it's clear that race is again involved in a statewide North Carolina political battle.

Yet times have changed in recent years. Obama retains a lead here. And Tuesday could be a watershed primary for a state bound by its history, proving that even in North Carolina, a black man can be nominated to the presidency.

To be sure, both candidates get support across racial lines. And yet the undercurrents are evident across the state, in the faces that congregate at Obama or Clinton rallies, in the advertisements clogging the airwaves, in the way some voters won't always elucidate their opposition to the other candidate.

"I think it's a racial thing instead of who's going to be the best president," said James "Tall Jack" Jackson, who is black and a member of Craven County's Democratic executive committee, after attending an event for Clinton last week.

"If Hillary wins it, some of the blacks are not going to vote [in November]," Jackson said. "If Obama wins it, some of the whites are not going to vote."

It was last weekend that Obama's former pastor, the Rev. Jeremiah Wright, returned to the spotlight. Obama immediately denounced Wright and his speeches, in which Wright said, among other things, that the United States was attacked on Sept. 11, 2001, because it had engaged in terrorism.

But the publicity hurt. Polls showed erosion in Obama's double-digit lead in North Carolina.

"I think it's given pause to some people who have been supporting Obama," said Hunter Bacot, a political science professor and pollster at Elon University. "And for others it's given them a reason to oppose Obama beyond race."

Three weeks ago, Bacot found in a statewide poll that more North Carolina voters would be reluctant to cast a ballot for a woman than for a black man.

But Bacot suspects that if he conducted the statewide poll again, the results would differ.

"I think race would rival gender," Bacot said.

Gina Gilliam, an Apex real estate agent, said she'll have a difficult decision to make if Clinton doesn't win the nomination.

Obama "doesn't have the experience and gravitas for this day and time," Gilliam said.

"I don't know where he will fall on issues," she said. With Sen. John McCain, the certain Republican nominee, "at least I know."

Gilliam spent her early years in California and says she was raised not to pay attention to skin color. She is not troubled by Obama's mixed-race heritage, she said, but she thinks that because voters outside Illinois don't know Obama, they rely on racial stereotypes.

"They color in the blanks," Gilliam said.

A tumultuous history

Racial issues have shaped North Carolina politics since the Reconstruction era. In 1880, The New York Times detailed county-by-county violations of white Democrats keeping black Republicans from voting. In Wilmington in 1898, whites rioted and forced blacks from their homes after a local election, the only known political coup in U.S. history.

In more recent years, former Gov. Terry Sanford lost the Tar Heel Democratic presidential primary in 1972 to Alabama Gov. George Wallace, a segregationist who made his name fighting school integration.

And then there was the Harvey Gantt/Jesse Helms U.S. Senate race of 1990. Helms, the Republican incumbent, was in a close race with Gantt, Charlotte's first black mayor, until airing a last-minute ad that showed a pair of white hands crumpling a rejection letter and blaming the job loss on affirmative action.

The mixture of race and politics doesn't happen only here. In 2006, black U.S. Senate candidate Harold Ford lost in Tennessee during a race in which his Republican opponent aired an ad showing a blonde white woman cooing "Call me." The ad referred to a Super Bowl party sponsored by Playboy magazine that Ford attended.

And it isn't just the South. In Pennsylvania's primary April 22, 13 percent of white Democrats told exit pollsters that race was a factor for them in the election. Among black Democrats, 4 percent said race was a factor.

U.S. Rep. Mel Watt, Gantt's campaign chairman and former leader of the Congressional Black Caucus, said publicly last year he feared America wasn't ready to elect a black man as president.

Watt reversed that view a month ago, endorsing Obama and saying he was "pleasantly surprised" at how whites have backed the Illinois senator. He sees a dichotomy between a younger age group, for which race is virtually no factor, and an older group, for which race is a personal and troubling issue.

Watt said last week he thinks voters will search their souls before casting votes against Obama.

"People are going to ask themselves, 'Do I want race to be a factor in this day and time? Or am I ready to move on?' " Watt said.

Race and TV ads

Racial undercurrents have affected other contests too -- and they can be used to manipulate black or white voters.

In the Democratic gubernatorial race, state treasurer Richard Moore linked Lt. Gov. Bev Perdue to the Ku Klux Klan in advertisements.

The N.C. Republican party aired commercials tying both Perdue and Moore to the Rev. Wright despite requests from McCain and the national Republican establishment to hold its fire.

"Although both parties claim they don't, they have racial overtones," Bacot said of the ads.

Among voters, some Clinton supporters in North Carolina say they would vote for McCain in November if Obama wins the nomination.

Greg Gallagher, 52, a construction worker who lives in Pamlico County, was so uncomfortable hearing about Obama's pastor that he worries about the candidate himself.

"The more I know, the less I like him," said Gallagher, who is white. "You listen to this guy -- it's not going to pull people together. It'll break them apart."

Duke University associate professor Kerry Haynie, co-director of the school's Center on Race, Ethnicity and Gender, said last week that Obama has been "racialized." The senator may draw skepticism from whites, Haynie said, if he is perceived as being popular among blacks.

Bev Barksdale, 48, a bartender in Oriental who worries most about health care, said she e-mailed Clinton last week advising the senator that black voters in Eastern North Carolina will come out for Obama.

"I said, 'You need to come further east.' In the counties, people are uninformed, uneducated and black," said Barksdale, who is white. "I'm not a racist, but I think a lot of black people are coming out to vote because of the race issue."

Like Gallagher, she would vote for McCain or not at all before casting a ballot for Obama. She said he has too little experience, and she doesn't think he's willing to pledge allegiance to the flag.

"That is huge to me," she said.

(Obama has led the pledge in the U.S. Senate.)

Some of Obama's supporters seem less likely to vote for McCain if Obama is not nominated. Those at the Durham rally said over and over again they would vote for Clinton, despite concerns about her honesty and campaign tactics, before supporting McCain.

"The Republicans have made a mess of things," said Freddie Rogers, a retired school maintenance employee who lives in Durham. He is black.

Getting beyond race

Despite polls showing some white discomfort with Obama, most voters appear to have worked consciously to move beyond race.

In Kinston, Daniel Adams, a 30-year-old scientist, recently switched his registration from Republican to Democrat ("It's like someone who's just finished AA," he said jokingly.)

A native of Eastern North Carolina who has lived and worked abroad, Adams has grown used to -- if frustrated by -- the racism he hears from extended family. They always vote white, he said.

"I think race always plays into decisions, especially with politics, especially in the South," said Adams, who is white. He wanted to break that mold. And so for the longest time, Adams liked Obama's idealism.

"I once thought he could change the country," said Adams.

But he has lost some faith in Obama now, wondering how the man could sit for 20 years in Wright's pews. Adams will vote for Clinton in the primary.

At the Chavis Park polling place in Raleigh on Saturday, Schalanda Williams, 25, a stay-at-home mother, finds hope in the campaign.

Williams, who is black, said Obama's candidacy has turned a corner for potential black leaders. Now, she said, she can tell her three young children that they really can become president.

"It is what it is. There's always been racism, and there will always be racism," Williams said.

"Hopefully it'll get better."

(Staff writer Rob Christensen contributed to this report.)