Devolves

verb

1. To roll (something) down; to unroll.
2. To be inherited by someone else; to pass down upon the next person in a succession, especially through failure or loss of an earlier holder.
3. To delegate (a responsibility, duty, etc.) on or upon someone.
4. To fall as a duty or responsibility on or upon someone.
5. To degenerate; to break down.

   "A discussion about politics may devolve into a shouting match."