A major union, the United Food and Commercial Workers, is beginning a new push to unionize workers at Wal-Mart (WMT). Congress has been working on new legislation that would make it much easier for labor to bargain and set up contracts. A numbers of companies, both large and small, are lobbying to keep the bill from making it to the president's desk.
Wal-Mart argues, with a fair amount of logic, that a unionized labor force would raise its costs and lower its ability to run its operations. Since its workers currently have almost no leverage with the company, those facts are almost certainly true. That bring the issues down to whether Wal-Mart's shareholders and customers are well-served by the company having a largely unionized work force. The answer is almost certainly "no."