Sounds like the premises of ‘The White Knight’ comic...
I get the hate for The Bat from a modern day point of view but I always looked at him and Gotham as how they begun in the early 30s: Gotham is the epitome of everything which was and is wrong with America, a lost city which is corrupted to its very core, the police, the politicians are all working for the mobs,(meta) humans etc. A surreal reality. Almost every origin story starts with Batman and Gordon trying to end the Injustice etc.
His first enemies are always the cops cause they’re harming the citizens of Gotham instead of protecting them. ‘The Master Race’ from Frank Miller touches that subject very well.