Why is the American public misinformed?

The American public continues to be misinformed by the mass media. But why is this? Where is the truth in political journalism. What happened to the time where American citizens could trust their news??? There are many reasons that the American public continues to be misinformed. 1. Is it because the mass media buys into the government propaganda? 2. Is it because the government exercises its power to portray the image they desire without regard to truth? 3. Is it because the mass media has its own agenda and its own image to portray? or 4. Is it because the mass media can now only seem to be left or right, liberal or conservative. So, therefore they only report according to their viewpoint, like CNN or FOX news? Personally, I believe that its a combination of all of the above. But mostly, it seems to be all about who has the power. Because when it comes to the media and politics- "power defines the truth." So bloggers out there, What do you think?