The thesis for the essay I'm writing is basically that those with the ability to control language are able to assert power over others. My teacher wants me to pull an example out from real life, so I figured the Nazi Party likely exemplified this idea.
Would anyone be able to point me in the right direction in regards to a reputable source which discusses this?
Just a quick note: you might be interested in our six-part series, "Finding and Understanding Sources". This should "help you help yourself" in your research on this or other relevant examples.
What you want is Victor Klmeperer's book The Language of the Third Reich, it's most recent English edition from 2006. Klemperer, a Jew married to a gentile living in Nazi Germany as well as philologist examined Nazi language and its political purposes and uses.
A further list of resources can be found via the USHMM.