We all mistake repetition for accuracy, a phenomenon called the illusory truth effect, and knowledge about the subject matter doesn’t necessarily protect you. Even a single exposure to information that sounds like it could be quasi-plausible can increase the perception of accuracy.
Back when I followed the efforts to counter the then-nascent Holocaust denial movement, I saw examples of this very phenomenon play out time and again. The mere restatement by Holocaust deniers of something that had no demonstrable reality was reality enough for people who took emotional comfort in it, whatever it might have been. Even people who didn't know they could be taken in by such bombardment were suckered by it once it came along.
Time and circumstance have since convinced me that a great many more people than we would initially think are like this. Deep down they may harbor what amount to paranoid suspicions about the world, but they don't voice them, or they discount them heavily. Then suddenly everyone else is talking about them — no, not just talking about them, but normalizing them — and what used to be fringe lunacy is now a staple of public discourse.
I used to think people could be divided neatly into two categories. Over here you had the people who were sincerely interested in the process of truth, and over there you had the trolls. What I'm finding is that there are a lot of people milling around in the middle who can be tricked into becoming trolls-by-proxy. They are easily tricked because they are not familiar with the ways their own psyche can be carpet-bombed into submission by the blunt-force trauma of lies passed on from emotionally trustworthy comrades. It's not that they don't care about the truth; it's that they care more about the fact that someone close to them has clued them in on things, or so they think.
I was worried enough about this phenomenon even when it was confined to some dingy corner of public life. But now it's seized the commanding heights of power, and those who try to correct the record by way of easily checked facts are the ones branded as malicious liars.
I don't see any of this ending well, but I'd rather be on whatever side of history valued verifiable truths over comfortable lies.