In preparation for November's congressional elections, senior Democrats have launched a series of attacks against Wal-Mart, accusing the world's largest retailer of failing to pay its workers a living wage or provide adequate health benefits.
In recent weeks, Joe Biden and Evan Bayh, both senators, and John Edwards, a former senator - all of whom are contenders for the Democratic presidential nomination in 2008 - have criticised the corporation and said its business practices are undermining the American middle class.
"My problem with Wal-Mart is that I don't see any indication that they care about the fate of middle-class people," he said in a recent speech. "They talk about paying them $10 an hour. That's true. How can you live a middle-class life on that?"
Mr Bayh, from Indiana, said: "It's not anti-business; Wal-Mart has become emblematic of the anxiety around the country and the middle-class squeeze."
Attacks on the retail giant from the left are nothing new, but the recent wave of attacks from Democrats appears to be part of a co-ordinated strategy ahead of November's mid-terms to try to portray the party as a champion of middle America and a campaigner for egalitarianism.
Democrats alleged that fewer than half of all Wal-Mart employees are covered by the company's healthcare plan and that the average worker earns less than $20,000 a year. Wal-Mart says its wages are above the national minimum wage and that 150,000 Americans who would otherwise not have healthcare plans do so because of its schemes.
There is a danger that the Democrats' attacks could see it lose support from some Wal-Mart workers. The company has responded to the rhetoric by telling its workers of the attacks that politicians have been making, saying: "[We] would never suggest to you how to vote but we have an obligation to tell you when politicians are saying something about your company that isn't true."