The story
From spin (“a favorable comment or interpretation”) + doctor. First use appears c. 1984 in the New York Times.
Etymology from Wiktionary, CC BY-SA 4.0.
spin doctor
Today it means: A person employed to gloss over a poor public image (or present it in a better light) in business and politics, especially after unfavourable results; a lobbyist; a PR person. Full definition →