Photograph of Obama, Clinton and Edwards at an event in Columbia, S.C. by Elise Amendola/AP With the South Carolina's Democratic primary on this coming Saturday, the three leading Democratic candidates, Hillary Clinton, Barack Obama, and John Edwards gathered together at a Martin Luther King Day Jr. debate in Columbia, S.C. When Clinton addressed the crowd, she said, "We have come so far together. Barack Obama, an extraordinary, young African-American man with so much to......