WASHINGTON -- The Teamsters Union said it has been told by officials in the Transportation Department's Federal Motor Carrier Safety Administration that the first Mexican trucks will be coming across the border on Saturday. The union said Wednesday it would ask a federal appeals courts to block the Bush administration's plan to begin allowing Mexican trucks to carry cargo anywhere in the United States. Teamsters leaders said they planned to seek an emergency injunction Wednesday from the Ninth Circuit U.S. Court of Appeals in San Francisco. "What a slap in the face to American workers, opening the highways to dangerous...