I've seen The Dark Knight probably around 20 times. It took me until seeing it at an old theater in Nashville over the weekend to realize something about the Gotham of the Nolan trilogy. It has crappy health insurance coverage. And the lack of coverage helped lead to the death of Rachel Dawes, the creation of Two-Face, and the turning of Batman into The Dark Knight.
Like all Nolan movies, he drops a hint about what will happen in the movie very early on. After the opening of the Joker heist, we cut to Gotham at night. Two guys are about to make what looks like an illegal drug deal when one of them looks up and sees the Batsignal in the sky. He walks away from the deal for fear that Batman will stop him. Then we cut to Gordon on top of the Major Crimes Unit roof, where he has turned on the Batsignal, waiting for Batman to come talk to him.
Detective Anna Ramirez joins Gordon on the roof with a cup of coffee and asks if he, "Ever plans to see his wife again." To which Gordon responds, "I thought you had to look after your mother, Detective." Ramirez says she checked her mother back into the hospital. So it sounds like Ramirez is the only person her mother has to look after her, an emotional and likely financial burden.
As the movie unfolds, we are shown numerous times where the mob is a step ahead of the police. At the scene where Lao tells the mob that he has to move their money to keep it from being taken by the cops, he says that he knows the cops are planning to take their money through, "Mr. Maroney's well placed sources" (cops that are working with the mob). Later, when the cops are transferring Harvey Dent from the MCU to County General, the Joker attacks the convoy. After the Joker is captured, Harvey is put in a car driven by Detective Wertz so that he can presumably be cleared of being Batman and go home. Once put in the car, the camera lingers on Ramirez, who helped him into the car. This is foreshadowing Ramirez's betrayal of Dent by being the one who gives the Joker Rachel.
After Rachel is killed and Harvey decides to be Two-Face, he confronts Wertz about turning him over to the Joker and asks who the other cop was that gave Rachel to the Joker. Wertz doesn't know. So Two-Face goes to Maroney, who tells him that it was Ramirez. Two-Face confronts Ramirez who says that the mob "Got to her early on" because of her mother's hospital bills. So Ramirez works with the mob so she can make some money on the side to help her mother, who because she's seemingly sick all the time, can't work and can't afford health insurance.
The movie came out in 2008, before the passing of Obamacare (aka, The Affordable Care Act). If the world of Nolan's Gotham had implemented a version of Obamacare, Ramirez's mother may have been able to find health insurance on the exchange. Or if the state Gotham resided in had a Democratic governor or a halfway sane Republican governor, Ramirez's mother could have enrolled in Medicaid. With her mother having health insurance, Ramirez wouldn't have been tempted by the mob. Without cops to help them, the mob and the Joker are less able to capture Rachel and Harvey. And without Harvey Dent's turn into Two-Face, Batman doesn't have to become the villain.
Of course, Batman probably wouldn't be needed in the first place if Gotham would address it's inequality problem. Then Joe Chill wouldn't need to steal from and murder rich people in allies.