Anna Rascouët-Paz relates an explanation (from someone who worked in a past administration) for Trump press secretary Spicer’s repeated lies about inaugural crowd size. It’s spot on:
For more on a disinformation strategy based on insisting that nothing is knowable, see The Russian Conspiracy on Behalf of Conspiracy Theorist Donald Trump (“there is a coherent pattern to the discourse he has promoted. It is a comprehensive attack on empiricism. He spreads distrust against every institution, so that the only possible grounds for belief is trust in a person. The suspicion he spreads against every institution protects Trump from accountability.”) and For Mr. Trump, It’s STEM, Schwem, Whatever… (“he insists that the truth is indeterminable whenever he wishes to evade responsibility for his own lies.”).
For Spicer’s calculated statement to undermine truth, see The White House Press Secretary Makes A Statement.