Journalists work in every area of the media not only newspapers but tv radio and online. Certain newspapers follow a certain political parties whilst others claim to be independent.
How would you judge truthfulness of a story if a left wing newspaper revealed aspects of a tory politian's life while a right wing paper gave a different view (or didn't run the story ). answer is you can't yophave to make your own mind up . Same goes for tv and radio.
If all journos follow one party line (as in China and Burma) where the media is state controlled then you have just one view and nothing else is allowed.