BANGKOK (AP) -- For President Barack Obama, expanding U.S. influence in Asia is more than just countering China or opening up new markets to American businesses. It's also about building his legacy.Fresh off re-election, Obama will make a significant investment in that effort during a quick run through Southeast Asia that begins Sunday. In addition to stops in Thailand and Cambodia, the president will make an historic visit to Myanmar, where his administration has led efforts to ease the once pariah nation out of international isolation.The trip marks Obama's fourth visit to Asia in as many years. With a second term now guaranteed, aides say Obama, who kicks off his schedule in Bangkok, will be a regular visitor to the region over the next four years as well.\Continuing to fill in our pivot to Asia will be a critical part of the president's second term and ultimately his foreign policy legacy