MARTINSVILLE, Ind. - Cafe owner John Doyle had some advice to serve up when a couple of Barack Obama's aides stopped for lunch recently in this diversity-challenged Indiana town.

"In this county, you guys are going to have to promote the white part of him,'' he told them.

"One young kid didn't know what I was talking about. He was from Iowa or something.''

At the best of times, Doyle thinks Obama would face a tough road in Martinsville in Tuesday's primary.

The town's residents have grappled for decades with a reputation for racial conflict that they're trying to overcome.

The Klu Klux Klan was once a dominant force in Indiana.

And Martinsville, a town of 12,000 still remembered for the horrific racial killing of a young black woman in 1968, shares the nearly all-white demographics of many rural conservative spots.

Now saddled with an anti-American rant from his ex-pastor Rev. Jeremiah Wright, Obama might have an even higher hill to climb among those who already view him with suspicion.

Wright's various incendiary remarks include a claim that the U.S. government developed the AIDS virus to infect black people.

But Doyle, for one, doesn't think Wright has changed any minds about the Democratic front-runner.

"He just gave people who don't support Obama one more reason to dislike him.''

Pete Peterson, a retired Lutheran minister and college professor, sees it differently.

"Of course it hurt him. I'd be surprised if he did well here.''

"He's above everybody, unless his preacher gets a hold of him,'' Peterson says with a laugh as he strolls through the downtown square dominated by a red-brick courthouse where the last Klan rally was held in the 1960s.

"His pastor said it right -- he'll say whatever he has to say to get votes.''

A barrage of new polls since Wright unleashed a theatrical tirade last Monday -- and an angry Obama denounced him in a bid to limit the damage -- suggest rival Hillary Clinton is gaining some momentum in Indiana.

Obama's substantial lead in North Carolina, also voting Tuesday, seems to be shrinking. He has lost some ground in national surveys too.

Yet Clinton still faces a huge uphill battle. Obama has won more states, a larger share of the popular vote and more pledged delegates -- a tally considered impossible to overcome before primary voting ends June 3.

He is still picking up superdelegates -- elected Democrats and party leaders whose backing is essential to win the nomination -- at a steady clip.

But there's no doubt it has been a tough week for Obama, who was facing problems even before the pastor opened his mouth.

Obama was already losing ground among white working class voters who helped give Clinton a nearly 10-point win in Pennsylvania last month after he described small-town voters as "bitter'' over the terrible economy.

And there are a lot of older voters who feel as Peterson does -- that Obama is a Harvard-educated elitist with little understanding of life in places like Martinsville.

It's a view that's frustrating for the Obama campaign, considering that Clinton went to Yale Law School.

"Here,'' says Peterson, "everybody's the same and everybody looks out for everyone else.''

"The entitlement generation -- that's where he gets all this enthusiasm, from people who think they'll be getting something for free.''

"I like Obama,'' says 22-year-old Justin Shrout, a brick mason in Martinsville, but he shrugs when asked why.

"I wouldn't mind seeing Hillary either, but I'm not really big on Bill Clinton.''

Doyle named his cafe for his son Jeremy who died two years ago in Iraq. He hasn't decided between Obama and Clinton but supports their pledges to end the war.

Obama has a much more forceful fan in Jeff Main, treasurer for Martinsville PRIDE, a group dedicated to promoting the town as a welcoming community.

"'I've got an Obama bumper sticker on my car and I wrote a sizable cheque a while ago,'' he says.

"Do people give me the stink eye when I drive around? No,'' says Main, who believes Obama can deliver on bridging divides in the country while Clinton "is very focused on sitting on the chair'' in the Oval Office.

Main thinks most residents will vote for the person who speaks to them and their issues, not on the basis of race. "We're saddled with our fair share of small-minded, bigoted people, but no more than any other community.''

Many voters in Martinsville, like maintenance supervisor Joe Bryson, are focused on the difficulties of making their paycheques last.

With gas prices threatening to hit US$4 a gallon, Bryson has cutting back on some weekend activities with his seven-year-old son.

"I've not heard anybody say anything about race,'' says policeman Gary Wagner. "It's the war and gas, the war and gas.''

Ted Ellis, mayor of Bluffton about an hour away, is endorsing Obama because he thinks his approach is "more calm and reasoned.''

But race is an issue in his town, he says.

"I think a lot of undecided voters aren't really undecided. They're just not saying. Who will tell you that race is a deciding factor?''

Bluffton, like dozens of other Indiana towns, once warned blacks to be indoors by nightfall or gone from town altogether after spending the day working as porters and waiters.

"A lot of those mindsets die hard,'' says Ellis, who had welcoming signs promoting an "inclusive community'' posted at the town limits.

"You don't turn this ship on a dime. You just try and make sure you're not making any more mistakes.''

Sociologist James Loewen wrote about so-called "sundown towns'' -- no blacks after dark -- in a 2005 book of the same name. He says the legacy hasn't been eradicated although there has been progress.

"What's crucial in this campaign is whether or not the black candidate can get out of being a file-folder phenomenon. If he can manage to be seen as Barack Obama first instead of black, he might do quite well,'' says Loewen.

"He's been doing a good job until the Wright controversy.''