Sidney Stone Blumenthal (born November 6, 1948) is an American journalist and political operative. A former aide to President Bill Clinton, he is a long-time confidant of Hillary Clinton and was formerly employed by the Clinton Foundation. As a journalist, Blumenthal wrote about American politics and foreign policy. He is also the author of a multivolume biography of Abraham Lincoln, The Political Life of Abraham Lincoln. Three books of the planned five-volume series have already been published: A Self-Made Man, Wrestling With His Angel, and All the Powers of Earth. Subsequent volumes were planned for later.