In researching politics you should always remain aware of the source's bias. According to the American Heritage Dictionary bias is "A preference or an inclination, especially one that inhibits impartial judgment" or "An unfair act or policy stemming from prejudice." Newpapers, magazine and other popular media are particularly suseptable to bias.
If you are unsure if a source has a liberal, conservative or neutral slant, use the Checklist for Evaluating Web Sources, particularly the objectiving section to evaluate the source.
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