I am looking to replace the idiom "kangaroo court" in the following sentence:
Class followed its usual script. The professor took center stage, exposing the deep racism, sexism, colonialism and homophobia of a previous generation and like well-rehearsed actors, us students assumed our roles as moral arbiters in a kangaroo court.
I want the replacement to communicate the idea that the verdict or judgement is a forgone conclusion and that the trial/classroom is just a pretence of debate/justice as everyone already knows what the answer/verdict must be before discussion ensues.
If no good replacement can be found you could rewrite the sentence entirely to help communicate the above point.
Thanks a bunch.