Sometimes, it's hard to touch on profound topics such as racism, bad political agendas, and the evils of organized crime without being preachy or condescending. These issues tend to make us feel uncomfortable, especially if we're exposed to them every day. They make us realize that we've also unconsciously done our roles in being racists or biased against a particular group.
District 9 explores these negatives in a unique perspective. We don't see humans discriminate against other humans based on gender, race, or sexual orientation. The film makers ingeniously extend the context of discrimination, focusing on aliens.
Watch it. It's funny, profound, touching, and graphic.