punch down

Verb

punch down (third-person singular simple present punches down, present participle punching down, simple past and past participle punched down)

1. (intransitive, slang) To attack or target a group that is weaker or of lower status than oneself.
   • The anti-vaxx movement punches down and punches hard. Its leaders tend to be men and women from wealthy backgrounds. […] They draw a large part of their audience from the poor, the poorly educated and ethnic minorities.2021 January 30, Nick Cohen, “Anti-vaxxers posing as victims has a history. Look at Andrew Wakefield”, in The Guardian, archived from the original on 10 Mar 2023

   Antonyms:

   punch up

2. Used other than figuratively or idiomatically: see punch, down.