Apologies for the late reply. You're right about what they've attempted and will continue to attempt, of course. There is reason for hope, however. They had decades of experience manufacturing consent via print and broadcast media, and they got pretty good at it. Clearly they want to wield social media as deftly (see all the wishful thinking about the obviously-bullshit-from-day-one "Russiagate" theory). I don't think they have that skill yet, however. The current thinking is that they'll get it if they just deplatform the right people (and, it seems, the right platforms). That's a dead end; it runs counter to the way that social media works. Rather than swimming upstream, eventually they might develop effective mass communication methods via social media. I don't know what form those will take... maybe trolling-at-scale? They don't have it yet, though.

Another thing about "fear sells"... some fears are more comfortable than others. That's why it has taken so much work to get a tiny minority of Americans worked up about global warming, but they've easily stoked a series of stupid wars. It's comfortable to fear brown people, but it is less comfortable to fear things that seem fundamental to our own lives like the current form of our economy.