For the first time in a generation, because of the prolonged battle between Hillary Clinton and Barack Obama, the industrial and rural heartland of America, its declining rustbelt cities and culturally conservative Deer Hunter country, have become the focus of a Democratic primary race.

Once-booming but now decaying industrial cities such as Youngstown in Ohio and Allentown in Pennsylvania, unaccustomed to such attention in a primary campaign, have seen hundreds of journalists and camera crews following the two candidates in the shadows of shuttered factories.

This fascinating slice of America, which runs through Pennsylvania, Ohio, Michigan, parts of Indiana, northern Kentucky and the coalmines of West Virginia, is predominately white, working class, encompasses huge industrial cities and heavily rural farming areas, and has forced Mr Obama and Mrs Clinton to focus on such issues as free trade, the loss of manufacturing jobs and gun rights.

At the beginning of the year, few political strategists predicted that the race would last beyond the coast-to-coast “Super Tuesday” contests on February 5. Since then, as the contest has dragged on, the two competed in Ohio on March 4, Pennsylvania and will probably have showdowns in Indiana on May 6, West Virginia a week later, and Kentucky on May 20.

This has brought the two candidates through largely blue-collar territory where the demographics have favoured Mrs Clinton, a key component to her argument that she is more electable than Mr Obama. He garners most votes from young, affluent and black voters in big cities such as Philadelphia, but has struggled in smaller towns and rural areas.

In the central south of Pennsylvania, in towns such as Mercersburg and Altoona, the hostility to Mr Obama is obvious. It was this area, hit by hard economic times, that Mr Obama so offended when he said that small-town Pennsylvanians were bitter about their plight and “cling” to guns and religion. The area is almost all white, and blue-collar Democrats appear to be voting for Mrs Clinton. That includes Cindy Sowers, 48, a resident of Mercersburg, who is so angry at Mr Obama she made a “Not Bitter” sign and put it her front garden. “A lot of people are angry,” she says of Mr Obama’s comments.

This political terrain has injected issues into the campaign that neither candidate expected to be arguing about at the beginning of the year. They have both striven to appear more opposed to free trade agreements than the other, in a region where hundreds of thousands of jobs have been lost in recent years, and where foreign competition is blamed.

In Youngstown, Ohio, a boom area in the 1950s, the population has shrunk by more than half in the past half-century. The decline of the city’s industry and its adverse effects on locals became the subject of Bruce Springsteen’s ballad Youngstown. The singer has endorsed Mr Obama.

In a debate last week, the Illinois senator denied that he favoured a ban on handguns. It is an issue that will be used by Republicans to attack him if he becomes the nominee. In a poll earlier this week Mrs Clinton leads Mr Obama 56 per cent to 31 among hunters; and by gun owners, the former First Lady is favoured 53 per cent to 28.

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