But the agenda may be driven by other concerns that have been debated by the Latin American leaders long before they arrived for the summit.  Cuba, which is not a member of the Organization of American States, is not invited to join the 34 other leaders.  "This is a point of contention," said Ted Piccone, a Brookings Institution senior fellow who specializes in U.S.-Latin American relations.  "There is a lot of disagreement about the U.S. policy toward Cuba... Cuba doesn't have a democratically elected government and therefore doesn't meet the criteria," he said.  But that didn't stop Ecuador's leftist President Rafael Correa from stoking the fire to get Cuban leader Raul Castro a seat at the table.  Correa threatened to put together a boycott with other leaders in the Bolivian Alliance (Venezuela, Bolivia and Nicaragua), which led to intense diplomacy behind the scenes. Inviting Castro would have certainly caused problems for Obama, especially in an election year.  During the previous summit three years ago in Port of Spain, Trinidad, Obama had an uncomfortable encounter with Hugo Chavez, when the Venezuelan leader handed him a book critical of the United States and Europe.  Colombian officials were clearly aware of the potential fallout in this case, so the country's foreign minister was dispatched to Cuba. Colombian President Juan Manuel Santos himself then flew to Cuba to meet with Castro.  Those meetings effectively ended the dispute, but Ecuador's Correa was angry. He fired off a letter to Santos criticizing the veto of Cuba's participation as "intolerable."  Then he boycotted the summit, even though the other leaders who had supported his appeal confirmed they would attend.  Piccone, of the Brookings Institution, said some leaders in the region are frustrated with what they view as a leftover Cold War attitude in the United States toward Cuba, and they are pushing for changes.
President Barack Obama's trip to Cartagena, Colombia, will be historic from the moment Air Force One touches down on Friday. His weekend visit will mark the longest time a U.S. president will have...