Emma Mitts, a black inner-city alderwoman representing Chicago's 37th ward, loves Wal-Mart. In September the largest US retailer will open its first store within Chicago's city limits in her neighbourhood, bringing in much needed jobs and tax revenues.

This week Ms Mitts voted against a new law that would set a minimum wage for "big box" retailers such as Wal-Mart, Target and Home Depot that operate in the city - as opposed to its surrounding suburbs. The bill passed, by 35 votes to 14.