WHITEWATER, WI -- Star Packaging is all but silent a year after a raid by federal immigration agents. A lone machine clacked on a recent afternoon, a single worker sealing plastic bags around bundles of screws. Beyond him, a flank of packaging assembly lines stood motionless. Empty pallets were stacked to the ceiling, and the reaches of the 58,000-square-foot warehouse, once filled with goods received and ready to deliver, yawned wide. The Whitewater plant that once employed 100 workers now has fewer than 10. Its founder, scheduled to go to trial Monday, faces some 30 years in prison if convicted,...