punching bag

noun2

1. •
   (US) A tough bag, usually cylindrical, filled with air, sand, or other material, often suspended so that it swings freely, which is punched or kicked when practising sports such as boxing or martial arts.
2. •
   (US, figurative) A person serving as an object of abuse.

   • The response was swift, and [Harold] Bloom became a punching bag for leftist critics, who valued literature’s power to deliver social and political messages for the underrepresented. — 2025