Proving Media Bias

This is somewhat of a unique challenge to fellow RedStaters.  I am currently taking a political science course on the Executive Branch.  Recently the Professor asked us to pen an essay responding to the following statement.

“The media has become too biased (either left or right) and too negative in its reporting on the presidency.”

Even being the political junkie I am, having followed politics on a daily basis for years, I have no way of answering this question in one essay.  To an informed conservative it is like asking if bees make honey.  The whole existence of the media is to promote liberalism and the Democrats.  How can I possibly prove effectively that the media has been unprecedentedly bias towards Obama in the past few years?  They created him from nothing!  What are the five or six best tangible proofs, sources, references,etc. to effectively argue the conservative point of view.