Bias (n.) is best handled by declaring it: an honest writer shows where she starts from, so readers can correct for it.
Bias (n.) is rarely ordered from above in the newsroom; it arises from preselecting right-thinking people, internalized assumptions, and staff adapting to the limits of ownership, market and power.
Bias (n.) is an adjective handed out unevenly: a human-rights group is 'controversial... too sympathetic to the left', while the State Department, the main source, never gets an adjective at all.
Bias (n.) is complete when the writer cannot see it: a reporter finds 'clear choices' among El Salvador's right-wing parties and 'murky plans' in a Nicaragua whose ballot ran from right to far left — within one article.
Bias (n.) in favor of the state is invisible to anyone who has already taken all of the state's premises as given.