The media always gets the final word on how its subject gets presented. It tells a story, and those stories undoubtedly will hold inherent partiality.
Take Rupert Murdoch, for example, and his News Corp juggernaut. The Australian tycoon created Fox News in 1996 as a response to the ‘liberal bias’ he deemed to be rampant throughout the news. Nowadays, we can’t even say “Fox News” without immediately associating the channel with conservative ideals.
Now, in writing, there’s a little thing known as ethos. You probably learned about it sometime in high school English class, but in case you forgot, ethos is an attempt by a writer to appeal to the reader’s set of ethical values.