The powers that be are the people in authority, whoever they may be. The powers that be decided otherwise.
The vagueness is deliberate, since the phrase is used when naming anybody would be unwise. The powers that be is one of the last survivals of an old plural verb form.
1phrasethe powers that beThe people in authority, whoever they may be.
“The powers that be moved the whole department without asking anybody.”
the powers that be is a phrase.
Practised in Idioms