Duff received a BSFS degree in international economics at the Edmund A. Walsh School of Foreign Service at Georgetown University.
Immediately after graduation from college, Duff first worked on the House Select Committee on Assassinations as special assistant to the chief counsel, senior researcher, and public information officer.
She left to work for the re-election campaign of President Jimmy Carter at the Democratic National Committee and with presidential pollster Pat Caddell.
She organised high-profile events, including a $1,000-a-plate dinner at the Sheraton New York, which became a major display of her influence within Democratic circles.
Duff personally mobilised donors, worked phones to secure contributions, and used her East Side townhouse to host receptions for key figures, including Vice President Al Gore and Hillary Clinton.