Due to its 50-percent ownership of the Mexican trucking company TranssMex, Memphis-based M.S. Carriers should fare well if the U.S. ban against the use of Mexican trucking companies is finally lifted. Citing safety issues, former President Clinton imposed the ban which, in a recent ruling, was found to violate NAFTA regulations. President Bush, on the other hand, has long been an advocate of free cross-border trucking. This, of course, could not possibly have anything to do with President Dubya s alleged cocaine habit.