Presidential adviser and political commentator David Gergen has died at the age of 83. Gergen served alongside four presidents: Richard Nixon, Gerald Ford, Ronald Reagan, and Bill Clinton. He then spent some time as a magazine editor before going from political insider to TV commentator.

Gergen was 83 years old. His son, Christopher, told The New York Times on Friday that Gergen's death was caused by Lewy body dementia. Gergen first began working at the White House in 1971, where he started on the speechwriting staff for President Richard Nixon;