Naked Capitalism has the story Gaius Publius: The Clinton Campaign Notices the Sanders Campaign, or How to Read the Media.
But also, mainstream insider corporations are completely aligned with the insider game for the obvious reason — they’re part of it. No one inside the game wants to see it damaged. Hayes and Maddow, as people, may or may not prefer Sanders over Clinton, but MSNBC has a clear favorite and if you listen carefully and consistently, it shows. Their owners, and all of the other big media owners, can’t afford (literally afford, as in, there’s major money at stake) to play this one straight. You may find some unskewed reporting, but not a lot of it.
This article thoroughly uncovers the way news is subtly, and not so subtly, biased in favor of the insiders. The gist of the story shouldn’t surprise anyone, but the detail is interesting.