Today just seems to be a day of random thoughts, so why not go with it?
The way in which a person's bias can be most clearly seen is in the way that person evaluates evidence. I had a conversation over the weekend in which the matter of Bush being AWOL from the National Guard was proven by the fact that Bush could find only one old man who was a general at the time who was obviously partisan while a pile of papers showing that he was paid, had signed in for meetings in accordance with regulations and had partaken of the required physical examinations were not proof to the contrary. While it was never said out loud, the implication was that all of the "evidence" to the contrary was false, that they were lies.
It has been said that the playing of the "Liar" card must bring to a halt any principled or useful discussion. That is because the "Liar" card gives its user carte blanche to disregard any point or article of evidence on its face because of its presenter, not on its merits. Accusations of lying deny the opposition any opportunity to add value to the discussion by requiring that the accusers acceded to any new information being brought to the table.
It is in this way that any bias on the part of reporters becomes important. By deciding what evidence is important to the way a situation truly is, the reporter is the gatekeeper. This has to be done before the information is even discovered, a process that decides which questions need to be asked. For many years, the product of this process was the sum total of all of the information that was included in the public debate. As the ages old computer axiom goes: Garbage In, Garbage Out.