How to explain the relentless lying of left-wing politicians and much of the media

"... in the big lie there is always a certain force of credibility; because the broad masses of a nation are always more easily corrupted in the deeper strata of their emotional nature than consciously or voluntarily; and thus in the primitive simplicity of their minds they more readily fall victims to the big lie than the small lie, since they themselves often tell small lies in little matters but would be ashamed to resort to large-scale falsehoods."

In case you did not realise the quotation is taken from chapter 10 of James Murphy's translation of Adolph Hitler's Mein Kampf.