I responded to a boston globe article with the following. Movies do make you feel better and at times unite the masses. In the Dark Knight you see the world turned upside down with future danger inevitable. In the end of all great movies something ends and dies. Nolan doesn't want allegories galore, because he wants you to enjoy the art. If you want allegories then go see "There Will be Blood".
If you don't think this movie questions the major theories of a democratic society or the importance of a presidential election then you are mistaken. When electing a person into a government office you should look to the right person with a proven track record who you have a good feeling about. When a hero is faced with adversity you have a want him to throw the detonator out the window or sacrifice everything when even a gun is pointed in his face. This movie unveils everything good and bad about the human race. If that doesn't juice your roger, you can just take it for the fun art it is. Maybe then you're world will no longer be upside down, but instead it will be a brighter place with The Dark Knight.