Mexico described as "significant" the immigration-reform positions laid out by the administration of President George W. Bush on Tuesday, but said any U.S. plan would have to "recognize the contributions of migrants" and take into consideration those already living north of the border. Bush on Tuesday argued for his temporary worker plan for foreigners, hoping to win over skeptical conservatives with get-tough promises about illegal immigration. "The Mexican government considers it significant that the administration of President Bush has a solid and unified position on immigration reform that allows safe, legal and orderly migration, and takes into account those migrants...