Feb 22 2011 - The biggest form of media bias is not the slant to the left, it is to slant everything towards conflict, the more personal or salacious the better. As you examine the video you will notice that Mitchell takes every observation or even the slightest critique as an indication of dramatic personal conflict the likes of which one would only see in a show such as "The West Wing". In order to create this dramatic and combative narrative in her own mind Mitchell relies on statements and sources from people who were not "in the room" and were three or four levels down.
Combine the biases of conflict creation, dramatic theatre, and attention whoring with Andrea Mitchells left-wing slant and you can see that she ends up with a narrative in her own mind that she is certain is true, which has been reinforced by bad "sources" and her own biases.
Mitchell becomes incredulous while Rumsfeld simply explains to her that she just doesn't know what she is talking about.