A day after the last Maytag washing machine rolled off the production line in Newton, Iowa, last month, John Edwards, the Democratic presidential hopeful, was introduced at a campaign event in nearby Des Moines by one of the factory’s former workers.

Doug Bishop recalled taking his young son to meet Mr Edwards at a campaign rally in 2004, when the former senator was running for vice-president. “I’m going to keep fighting for your daddy’s job,” Mr Edwards told the boy, after hearing about the threat facing the Maytag plant. “I promise you that.”