I have a theory that in this new age of a billion ways to get information, people search for delivery systems that feed them the info that pretty much matches what they believe, with the slant they prefer...it has the built in feeling of being a trustworthy source, and this is perfectly fine, if not somewhat limiting exposure. but it's a wide open selection available to consumers now.
"the mainstream media", in my theory, is so huge in part due to the head start they had but as time and tech move quickly into the future, is also proving that the majority believes what they offer and prefers the slant they employ.
At the same time, they don't seem to have a yuuuge effect on elections. Anyone have stats on how many eligible voters actually vote? Certainly not a tremendous amount of the majority that prefers "main stream media" or only libs would be presidents, if the slant was as powerful as suggested.