From MarketWatch:

Citigroup Inc. lowered its rating on Wal-Mart Stores Inc. to hold from buy on Tuesday, citing concern that legislation intended to make it easier for employees to unionize would raise the retail giant’s labor costs and hurt its competitiveness. Deborah Weinswig, a Citigroup analyst, cut her price target on the Bentonville, Ark.-based retailer to $48 from $53…

The proposed Employee Free Choice Act, a top priority for unions this year, was formally introduced Tuesday by Sen. Tom Harkin, D-Iowa., and Rep. George Miller, D-Calif.
Wal-Mart would be the “primary target” if any such bill were to be passed, especially because the U.S. food retail industry has historically been unionized with the exception of Wal-Mart, which is the largest food retailer, she said.

Update:

John Duncan writes, “Very interesting, considering Wal-Mart hasn’t been at 53 in a couple of months. So Citibank is lowering its “target” from something that wasn’t very achievable to something close to where Wal-Mart is currently running, claiming that it’s the scary unions that are causing the problem. I call BS.”