Three of four men charged with illegally entering the New Orleans office of Democratic Sen. Mary Landrieu returned to court Wednesday for pretrial meetings with authorities. Suspects Defendants James O'Keefe, Joseph Basel and Stan Dai all carried suitcases and declined comment. The fourth suspect is Robert Flanagan. Federal authorities said two of the men posed as telephone workers wearing hard hats, tool belts and fluorescent vests when they walked into the senator's office inside a federal building in New Orleans on Monday. The other