Next-Door Neighbors Back Bush on Expanding Trade.

President Bush pulled the leaders of Mexico and Canada into an unusually direct involvement in his domestic political efforts to expand free trade on Tuesday when his two North American allies joined him in a foray into both Congressional politics and the presidential campaign. President Felipe Calderon of Mexico and Prime Minister Stephen Harper of Canada lent their weight to what has been something of a lonely campaign by the president as he has traveled the country to make pro-trade speeches and angry statements about the ''petty politics'' that he sees threatening one of his administration's major legacies. [ABSTRACT FROM PUBLISHER]