From the piece:
Wal-Mart's critics allege that the retailer is bad for poor Americans. This claim is backward: As Jason Furman of New York University puts it, Wal-Mart is "a progressive success story." Furman advised John "Benedict Arnold" Kerry in the 2004 campaign and has never received any payment from Wal-Mart; he is no corporate apologist. But he points out that Wal-Mart's discounting on food alone boosts the welfare of American shoppers by at least $50 billion a year. The savings are possibly five times that much if you count all of Wal-Mart's products.