It is Labour day in the United States, and President Barack Obama has spent some of the day campaigning in the crucial swing state of Ohio, reminding voters how important workers' rights are.

In the south, meanwhile, unions are fighting a losing battle to gain a foothold in manufacturing plants.

Republican state governments have undermined union rights across the south, encouraging some of the lowest wages in the country.

Companies like Michelin and BMW have been attracted to South Carolina, one of the many states in which workers do not need to pay union fees. Union organisers say the consequence has been to cripple unions.

The issue divides voters, and Mitt Romney, the Republican presidential candidate, has publically supported such policies.

Al Jazeera's Tom Ackerman reports from South Carolina.