You make a great argument, but I fear that until we have no global population of have-nots, even an educated society can fall victim to manipulatiors who need not believe their own rhetoric.
The key point to keep in mind, is that such mental phenomena underlie all widespread forms of social injustice. I think people who sincerely believe their own rhetoric aren't just as vulnerable. They are significantly more so.
"Of all tyrannies, a tyranny sincerely exercised for the good of its victims may be the most oppressive. It would be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated; but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." -- C. S. Lewis
Here, Lewis is speaking directly to internal psychological shortcomings and self awareness. The efficiency of "the enemy" is irrelevant. Here's another lesson of history -- Any ideology that heavily relies on the awfulness of an enemy to justify its own actions -- These should be highly suspect.
The key point to keep in mind, is that such mental phenomena underlie all widespread forms of social injustice. I think people who sincerely believe their own rhetoric aren't just as vulnerable. They are significantly more so.
"Of all tyrannies, a tyranny sincerely exercised for the good of its victims may be the most oppressive. It would be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated; but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." -- C. S. Lewis