Nancy Kadar was having dinner at a Wheeling restaurant a few weeks before the May 6 primary when an acquaintance leaned over from his table to talk a little politics.

"I hear that when Obama wins, they're gonna' call it The Black House," he grinned.

She did not grin back. Grimace? Yes. But to people like Ms. Kadar, a lifelong West Virginian weary of the stereotype of the backwoods rustic, this kind of stuff doesn't help.

"I guess I wasn't thinking that's the typical West Virginia thought," said Ms. Kadar, a hospital office worker.

How typically race informs the political ideals of West Virginians -- or Americans in general -- pushed its way onto the agenda after the May 6 primary when one in five Democratic primary voters said the race of the candidate they supported was important to them.

With Sen. Hillary Rodham Clinton taking 82 percent of that cohort and the number of black voters statistically negligible in West Virginia, the inescapable message became this: Some white voters just aren't going to support an African American.

"I think we would be naive to think that racial animus isn't already playing a role," said Kennon Rice, a professor of sociology at Albright College in Reading. "If there's any surprise, it's only to the extent that individuals are explicit about their racial animus."

This subject came up only obliquely in earlier campaign discussions. In many ways, say political experts, Mr. Obama's careful avoidance of discussions of race, his efforts to avoid being labeled the "black candidate" in ways that predecessors such as Jesse Jackson and Al Sharpton were, suggested that perhaps race would not play a meaningful factor in the contest.

"Obama has tried his best to be a post-racial candidate," said Dewey Clayton, a professor of political science at the University of Louisville.

Prior exit polls produced numbers showing voters in a variety of states -- including Pennsylvania and Ohio -- acknowledging that a candidate's race played a role in their decision-making. But in Pennsylvania and Ohio, sufficient numbers of black voters participated, making it unclear how many white voters were rejecting a black candidate.

In Texas, exit polls showed that while Mrs. Clinton won 52 percent of the one-fifth of voters who said the candidate's race was important to them, Mr. Obama won 47 percent of that same group, suggesting that Obama supporters might as easily have been supporting him because he is black.

"It's kind of a return to overt prejudice," suggests pollster John Zogby, who first noticed race as a voting factor prior to the Ohio primary.

"Maybe it didn't register with many of us how big that number is until it came to look more and more like it was going to be Obama" as the nominee, Mr. Zogby said.

In the wake of the West Virginia numbers, a number of political observers have recalled earlier episodes in which random voters expressed a dislike of a candidate based on race.

"When Obama won the Iowa caucuses, I had someone say to me, 'I'm changing my party if the gets the nomination.' I've heard many things similar to that," Mr. Zogby said.

With Kentucky's Democrats ready to go to the polls Tuesday, the West Virginia outcome is on the minds of people such as Mr. Clayton, the University of Louisville professor.

Mr. Clayton described himself as "dumbfounded" by the poll results as well as comments he heard from voters quoted on news channels, including the British Broadcasting Corp.

In interviews, he heard voters speaking bluntly about Mr. Obama's race as either a handicap in November against John McCain or as a reason they personally found him unacceptable.

"It amazed me how frank and candid and at ease they were saying this," Mr. Clayton said.

That bluntness made itself known earlier in the year when U.S. Rep. Ben Chandler, D-Ky., endorsed Mr. Obama. Mr. Chandler's congressional district is centered in Lexington and comprises an assortment of rural counties.

Staff members reported a flood of angry calls, some described as openly racial in tone, from constituents angry at the endorsement.

Mr. Obama, for his part, is spending much of the week not in Kentucky, a state his staff has all but conceded, but Oregon.

"She has a huge lead, about 3-to-1," Mr. Clayton said.

While some Obama canvassers have reported surprisingly hostile reactions from a handful of white voters during recent contests, the reports don't surprise, or especially alarm former Pennsylvania Sen. Harris Wofford. He is a veteran of both the Civil Rights movement and a noteworthy breakthrough presidential candidacy nearly 50 years ago, when John F. Kennedy sidestepped questions about whether a Roman Catholic could serve as president.

Much of Kennedy's support, Mr. Wofford said, stemmed from non-Catholic voters determined not to be labeled bigots.

"Many communities are going to feel stirred to protect their reputations," said Mr. Wofford, an active Obama backer.

Racial prejudice, he added, "is not a southern phenomenon anymore" and some of the rejection of Mr. Obama clearly comes from Northerners who were unlikely to stay with the Democratic party in November.

"A lot of the people for whom race matters a lot over the years -- firstly white Southerners, then the Northerners -- they've been voting Republican," he said.