ANOTHER ANTI-NAFTA pile-on is brewing in Washington this week. Even though the United States has gained jobs, wealth and goodwill from the regional trade pact, for years opponents of free trade have tried to persuade American leaders to ditch one of the agreement's most benign provisions -- allowing Mexican freight trucks onto American roads. When the United States signed the treaty in 1993, it promised to allow such trucks in, scheduling implementation for 2000. But lobbying from the Teamsters and others with economic turf to protect have held that up -- until now....
