His grease-covered hands tucked into the pockets of his blue jeans, his denim shirt streaked with oil, Chris Disinger stands in his car repair workshop amid the wasteland of shuttered and bulldozed factories and explains why he will not be voting for Barack Obama in the Indiana primary on May 6.

“Him being a black man - I have nothing against that, I've got nothing against anyone foreign - but I don't think he'll ever make it all the way,” Mr Disinger, a lifelong Democrat, says. “It's just his race. I'm afraid the man won't make it. I like Hillary. She's a Clinton. Bill did a lot of good things for this country.”

Two miles away, across the railway track and White River, which divides Muncie, from its blighted, blue-collar south to its university-campus north, from its dying industrial past to the espresso shops of its internet-age future, Angela Green, 21, has just ordered a soup and a salad at a sunny outdoor table.

“I prefer Obama over Hillary because of her bad personal life choice in staying with a cheating husband. That's not a strong-woman move. And this is a pretty Obama campus.”

For much of the past 100 years, Muncie, Indiana, has been one of the most studied towns in the US, since it became the subject of a landmark study of Middle America in 1924. Homogeneous, steady and conservative, it was picked by the husband and wife team of Robert and Helen Lynd to analyse the social and economic effects on a community of the rapid industrialisation of the 20th century.

Since the publication of Middletown: a Study in Modern American Culture, Muncie has been a national bellwether for marketeers and pollsters. If a soap sold in Muncie, it went national. The town has correctly picked every US president for the past century, with the exception of John F. Kennedy in 1960.

Today, for those wanting a nearperfect study of the way the Democratic battle has fractured along race and class lines, Muncie is the place to visit, 11 days before the next Clinton-Obama showdown in Indiana.

Muncie is divided between two alien worlds. The Southside was until the 1970s a booming industrial hub, full of factories, where workers boasted that they were part of the “car transmission capital of the world”. Today, it is all gone. A few hundred feet from Mr Disinger and his car exhaust shop sits a vast expanse of destruction, surrounded by barbed-wire fencing. Until recently it was the site of a General Motors plant, its soot-stained smokestack emblazoned with “Chevrolet”.

At one time it employed 3,400 men and women. Opened in 1934, it was shut in 2006, and this year it has been destroyed with dynamite. Near by sit other abandoned factories - BorgWarner, Indiana Bridge, Westinghouse - names that provided food and jobs for Muncie's southsiders but have now abandoned them.

At 6.30am each day in the nearby United Workers Auto hall, about 50 unemployed men from the razed GM factory sign in and sit around until 2.30pm, watching television and playing cards. They are paid to do this. General Motors has promised them other jobs, but nothing has materialised.

Leigh Baxtor, 51, who had been a toolmaker at the plant, said: “I am a Hillary Clinton supporter and intend to vote that way. She has the experience.” Of Mr Obama's message of “hope and change”, he adds: “That's a little bit pie in the sky”.

Four miles away, in another union hall whose factory will be shut next year, another member - who did not want to be named - was asked why the white, blue-collar community of Muncie seemed reluctant to vote for Mr Obama.

“Race,” he said, without a pause.

“Regardless of what you think, there is still a lot of racism in this country. It doesn't bother me, but I've heard people mention his middle name. It's Hussein. It's a Muslim name.”

North of town sits Ball State University campus and Ball Memorial Hospital, home to 20,000 students. Most will bolt Muncie once they graduate. It is the site of Mr Obama's Muncie headquarters. Mrs Clinton's is on the Southside. Both have campaigned here: Mrs Clinton in a school in the middle of town; Mr Obama at a ticket-only event on campus.

In the MT Cup coffee shop, students sit in front of wireless laptops. James Connolly, who runs the Centre for Middletown Studies at the university, said: “This is like two towns. There are people who have lived their entire lives on the Southside who have never set foot here. The white, working-class people in the Southside will vote overwhelmingly for Mrs Clinton. Here they will go for Obama.”

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