2) a radio station DJ, or MC at a club or event.
2) the club boom anniversary party spin doctor was awesome!
Most often this is in the political context, usually conservative, with the spin doctor masquerading as a journalist or "expert in the field" to lend credibility to what's actually just a PR line cooked up by the right-wing.
2. Slang for a disc jokey, especially of vinyl records and mixing.