Could someone please give me a defense of political correctness?

I am writing a paper on the subject and need a pro-political correctness argument. Since I am not exactly a proponent of the topic, I need someone to give me something. I would look online via Google, but I would prefer real people, or at least more real than those who wrote the articles I would surely find. In your responses, please be descriptive in your pro-political correctness argument and make sure it could withstand a formidable barrage of well-articulated points.