Diana West Tweeted this, in light of Trump's "failure to disavow":
She's quoting M. Stanton Evans's The Liberal Establishment, published in 1965 by the Devin-Adair company:
Perhaps the most awesome power of the national media—a power usually neglected in squabbles over "misquotation"—is the power to define the issues. While television and the magazines and the press cannot manufacture public opinion, they can in large part decide what public opinion will be about. They can zero in on certain matters to the exclusion of others, raise and reiterate certain questions, demand certain answers from one candidate while not demanding like answers from his opponent. This kind of influence was used repeatedly in the 1964 election.
Senator Goldwater and Representative Miller, for example, were often challenged to "disavow" the Ku Klux Klan and the John Birch Society. Lyndon Johnson, on the other hand, was not challenged by the media to disavow Americans for Democratic Action or the Socialist Party or the tacit support given him by the Communists. On the eve of the California primary Howard K. Smith, discussing the influence of the John Birch Society in that state, off-handedly described Goldwater as "their man." What would have been the outcry if a newscaster, discussing Communist interest in the election, had casually referred to Lyndon Johnson as "their man"?
As it happened, of course, the Liberal media did not even discuss the Communists' position in the election, much less pin them to Johnson. Similarly with Norman Thomas and his fellow Socialists. While Thomas campaigned for the Johnson-Humphrey ticket, no Liberal newsman called on these worthies to disavow his support. In short, the media effectively defined the scope of the extremist issue by limiting it to people backing Goldwater, and therefore defined it completely in Johnson's favor.
And earlier than that, “They'll Think You're Signaling”! Dog-Whistles From Goldwater To Reagan To Palin, which describes CBS reporter Daniel Schorr's attempt to smear Barry Goldwater as a Nazi—a smear so baseless that the president of his network made him apologize on air.