That's what one hears as the giant retailer sops up the vitality from middle-class families, local communities, and the national economy . This happens in three different but related ways. First, there's the clobbering of Main Street: Wal-Mart moves in on the edges of towns, and the much smaller downtown merchants, unable to match its prices, soon go under. Second, there's the miserable wage and benefits package offered by Sam Walton's creation. And third, there's Wal-Mart's purchasing strategy, which seems to be about buying American-made products only as a last resort -- to the point that today Wal-Mart, by itself,...