Bias makes people deaf, dumb and blind. Each time the "progressives" write something about this issue they expose more and more of their own deep-seated prejudice and they cannot see this. I would not label them progressives in the contemporary political sense. They are elitist in their philosophy.
Arrogance: "a feeling or an impression of superiority manifested in an overbearing manner or presumptous claims."“ Websters Collegiate Dictionary.
The word is well-defined in sentences like these from the liberals:
[Via NewsBusters.org - Exposing Liberal Media Bias] Posted by zexx at March 18, 2006 11:02 PM | TrackBack[T]he right™s sustained accusation of "bias" is both a powerful organizing tool...and an effective way of "working the refs." Knowing that they face constant charges of bias, reporters respond by bending over backward to show how tough they can be on progressives and Democrats. In contrast, when Media Matters for America criticizes the news media, it’s for a simple reason: we want them to do their jobs and do them right.
There may be no more profound difference between the left and the right on media issues than this: progressives believe in journalism.