BENTONVILLE, Ark., Oct. 26 - Inside a stuffy, windowless room here, veterans of the 2004 Bush and Kerry presidential campaigns sit, stand and pace around six plastic folding tables. Open containers of pistachio nuts and tropical trail mix compete for space with laptops and BlackBerries. CNN flickers on a television in the corner. Spencer Tirey for The New York Times Wal-Mart's team of marketing specialists works in a second-floor conference room at the company's headquarters in Bentonville, Ark. A documentary about Wal-Mart Stores is to open today in theaters. The phone rings, and a 20-something woman answers. "Turn on Fox,"...