Hillary Clinton, the most likely Democratic presidential candidate for 2008, is under fire within her party for reasons that would baffle observers in other countries. Senator Clinton stands accused of having spent six years on the board of the most prolific job creator in US history. Unfortunately for her, the company is Wal-Mart, the chain of cut-price "big box" stores that has become a rallying point for political activists. The staggering scale of Wal-Mart's operations is familiar. It turns over $300bn (£174bn) a year. If it were a country, its economy would rank ahead of Pakistan's. Its imports account for 10 per cent of the US trade deficit with China. There are as many Wal-Mart employees (1.3m) as there are US military personnel. Or Estonians. Or residents of Washington, D.C. and Boston combined.

The main gripe against Wal-Mart is that these legions of workers are treated badly. Wal-Mart does not like unions. It closed a store in Canada rather than allow its employees to set one up. Wal-Mart can charge low prices because it cuts costs (including wages and benefits) to the bone. Its workers make, on average, just under $10 an hour, which is well above the minimum wage but far from a living one. Less than half of the children of Wal-Mart employees are covered by private health insurance. As a result, 5 per cent of its employees use Medicaid, the government-funded health programme for the poor.