The humor is essentially dark for a cartoon and sophisticated. But at the same time, being a cartoon gives the writers more freedom than in a normal sitcom. It always pushes the line that, despite human failings, the Simpsons are really decent people.
“A good leader takes a little more than his share of the blame, a little less than his share of the credit.”
“What is inherently wrong with the word 'politician' if the fellow has devoted his life to holding public office and trying to do something for his people?”