premise: Caroline Kennedy served as president.
hypothesis: Caroline Bouvier Kennedy ( born November 27 , 1957 ) is an American author , attorney , and diplomat who served as the United States Ambassador to Japan from 2013 to 2017 . Early in the primary race for the 2008 presidential election , Kennedy and her uncle Ted endorsed Democratic candidate Barack Obama for President ; she later stumped for him in Florida , Indiana , and Ohio , served as co-chair of his Vice Presidential Search Committee , and addressed the 2008 Democratic National Convention in Denver .