[TopHand]

What politicians know that the authors of this study don't seem to realize, is that if we are told the same story repeatedly for long enough, no matter how absurd, we'll start believing it. If you throw in some scary outcome if we don't believe the story, we'll come around sooner. It seems that fear will cause us to re-examine our beliefs and values.

[Majromax]

That's the illusory truth effect (https://en.wikipedia.org/wiki/Illusory_truth_effect), which is one of the understood cognitive biases.