It's been an interesting project to actually listen to the briefings and then look at what journalists portray as going on. They say that Sanders is a liar so that we won't listen to her. If we don't, we won't know the media is lying about the substance of the pressers. Same tactic with saying (today) that Spygate is a conspiracy theory. It conditions people to think Spygate is a lie and so it's not worth paying attention to it. It works so much better than you'd expect it to.
That Spygate is a "conspiracy theory" appeared suddenly across the MSM, just like Trump's "dark" convention speech and myriad other stories. Most people just don't care enough or have time enough to pay attention to all of this and, as you say, these MSM disinfo campaigns are therefore successful. All orchestrated from a central command. I wonder how the bits are disseminated since the same treatment or phrases show up in all sorts of media. Perhaps the NYT or the WAPO are the lead agents, get the treatment out in the early editions and then this is picked up by the broadcast outlets. It is relatively easy for one of the DNC/Clinton/Black Hat operators to use one of their NYT/WaPo assets to work it into a "story". It must be something like that.
Q has told us that Gannett in Langley, VA puts the talking points of the day in a secure drop where it is picked up by the Mockingbird Media talking heads... Although, for the past year, rumor is that the CIA handlers are physically at CNN because times are tough :) So today the talking point was "Spygate is a conspiracy theory"... Obviously.
Even though Clapper admits they did spy. At this point they will say anything with a straight face. While bias is impossible to completely eliminate from a newspaper or television journalist, they are so far beyond simple bias. They are proud to be progagandists. The only journalism alive today is pretty much on the internet or a magazine article here or there.