One way to look at it is that the film is a commentary on the toxic effects of traditional masculinity. The main character, Travis Bickle, is a loner and a misfit who turns to violence and isolation as a way to cope with the world. He is a product of a society that tells men that they have to be tough and self-reliant, and that they should not show any emotion. This pressure creates a fragile masculinity that is easily broken, and that can lead to destructive behaviors like those that Travis exhibits.Another way to interpret the film is as a critique of the American dream. Travis is a Vietnam War veteran who comes home to a country that does not seem to care about him or his experiences. He tries to find a place in the world, but he feels like an outsider everywhere he goes. He turns to violence because it is the only thing that he feels he can control. In this way, the film is a commentary on the idea that the American dream is not accessible to everyone, and that some people are left behind in the pursuit of it.