That such a ____ of precedent would be countenanced was itself unprecedented in the court, a bastion of traditionalism.
I am practicing for verbal test in GRE therefore its very important to break down a complex sentence to simple sentences and moreover its better to guess a word for the blank space.
What bothers me is that the above sentence has "would be" and "was" in a complicated way. Can you please how to break down the sentence therefore I can easily understand the sentence and guessing for the blank would be easier.