Answer:
The revolving door
Step-by-step explanation:
In politics, the revolving door is a term that refers to the movement of high-ranking personnel from the public sector to the private sector, and viceversa. In our example, we can clearly see this: a person holding a high-ranking public post (presidential speech writer) moves to the private sector (writing as a columnist), and later returns to the public sector again (domestic policy adviser to a member of Congress).
The revolving door is generally frowned upon by the public, as conflicts of interest may arise: people in the public may favour certain parties, expecting to be rewarded with a good paying job in the private sector once his term in public office ends; and conversely, people with vested private interests might take a public post, expecting to enact legislation or act in a way that will further their own private interests.