Paul Kay of Language Log is puzzled by a bit of Washington jargon:
It’s easy to see what Ms. Stolberg intends by the “reverse revolving door” because we’re familiar with the revolving door as a characterization of the frequent passage from government official to lobbyist. What’s less apparent is why the trope works in the first place. It’s in the essence of a revolving door to permit simultaneous traffic in both directions. So what on earth could a reverse revolving door be?
When I first heard of “the revolving door” in the sense described (twenty-odd years ago), I think it had to do with the Executive Branch rather than the legislature. Legislators are rarely hired for their expertise in a specific area (other than politicking), but regulatory agencies and procurement offices take people from the industries directly concerned, because that’s where the expertise is. Thus it seems that the metaphor arose in a field where it was apt and drifted to one where it is less apt.