@hightor,
I think that's essentially right. The American example has corollaries in Australia and Britain where Murdoch has also been very influential in gathering up the local retrograde population and feeding them the sort of rhetoric and worldviews and sense of victimization (some surely justified) Didion and other write about. Because of settlement patterns (which cultural groups out of Europe settled here or there) and degree of isolation or forced cosmopolitanism, we end up with inevitable divergences like this.
As to Limbaugh, I don't see a great difference in what he says about Trump and followers from what he said about Bush Jr and his base. Or, though not so acute, what he said about McCain and Romney and their followers. His function is the same as Murdoch's - forwarding the electoral chances of the party which will best achieve a social and regulatory regime favorable to those who wish to control/influence society through and for wealth accumulation.
When Limbaugh says that only Trump can screw things up with his base, that might be true. But I don't see any way to count on it happening given the level of tribalism, the isolation of this base in a closed epistemology, and the degree towards serious authoritarianism they are clearly willing to move. I think most of them are a lost cause outside of some really serious national conflagration.
And that's why I don't agree on what you posit as "the only effective strategy". My notion is that this must arise from an address to those who aren't fruitcakes and those who flirt less seriously with fruitcakeisms. Jay Rosen said recently that he didn't think the media can stop Trump, that it will have to be the people. But his meaning here was that the press can't do the task on their own. He certainly doesn't believe the media ought to shut up.
Bad consequences from this administration - consequences that seriously and negatively affect large segments of the population including his base will be important. But we know enough about states like Kansas or Wisconsin etc to predict that degrading life circumstances can be effectively mis-diagnosed and mis-comprehended via effective propaganda. So we can't count on just that alone either.
