Yeah, that's one of the primary ways this happens: A populace is feeling desperate and hopeless, and falls for the promises of a shameless con man who says "I alone can fix this". This is just boiler plate stuff, it's certainly no secret, and they STILL fell for it.
In this particular case, though, that portion of the populace had been warmed up to desperation long before the con man, by a media that had created its own insulated, paranoid propaganda system. They were all ready for him, he saw that, and he ran with it.
So while most of this is old and historical, that part of it is new.