David Gergen, ex-adviser to Republican and Democratic presidents, dies aged 83

David Gergen answers a reporter's question in the briefing room of the White House, in Washington on 7 June 1993. Photograph: Doug Mills/AP

David Gergen, a veteran of Washington politics and an adviser to four presidents, Republican and Democrat, in a career spanning decades in government, academia and media, has died. He was 83.

Gergen was perhaps best known for a line he summoned for then presidential candidate Ronald Reagan for a TV debate with Jimmy Carter: “Are you better off than you were four years ago?”