"The question still remains, though: what the hell happened? How did a fact-free conspiracy theory come to gain so much traction among mainstream Americans? How were millions of people persuaded to invest hope in a narrative that anyone objectively analyzing the facts knew to be completely false?
The answer is that they were told that the Russiagate narrative was legitimate over and over again by politicians and mass media pundits, and, because of a peculiar phenomenon in the nature of human cognition, this repetition made it seem true."