"I'll make public opinion out there within five hours. I've done it all my life. I'll blacken this punk so that he'll--You leave public opinion to me. Now, Joe, I think you'd better go back into the Senate and keep those senators lined up."
--James Taylor (Mr Smith Goes to Washington)
The theory might be explained as follows. Intellectuals and their associated intelligentsia control the large media pipes for putting their socialist ideology in front of information consumers. Research suggests that not only will leftist journalists distort information conveyed thru the pipe, but they will likely grossly exaggerate it in order to influence consumers.
Even if consumers know that media is biased left, they are still likely to be influenced by it. One reason is that information consumers generally underestimate the extent to which media sources are operating strategically. This would hold true even for seemingly sophisticated media consumers such as politicians.
Sprinkle in propositions regarding the dominant direction of resource dependence in media:politician relationships, and you have the makings of an interesting theory.
A more general form of the theory might posit that any influential media source with a particular political ideology is likely to influence political parties that share some of those beliefs. When that is the case, the media source 'hooks' the party and that party can be subsequently shaped.
That would suggest, for example, a Fox News:Republican Party dyad that parallels the originally proposed MSM:Democratic Party dyad.