Agence France-Presse: The plan to build a vast oil pipeline from Canada to the southern shores of the United States faced congressional opposition Tuesday amid fierce anger over the Gulf of Mexico spill. Top US lawmaker Henry Waxman called on Secretary of State Hillary Clinton to block the proposed 2,151 mile (3,461 kilometer) Keystone pipeline, which would transport crude from Alberta, Canada to refineries in Texas. In a letter released on Tuesday Waxman — who chairs the House of Representatives …