His supporters are aware of—and love—the lies and hypocrisy. It serves to strengthen his appeal. See this paper by , , and
Quite Relevant: The Authentic Appeal of the Lying Demagogue: Proclaiming the Deeper Truth about Political Illegitimacy - Oliver Hahl, Minjae Kim, Ezra W. Zuckerman Sivan, 2018
Voters who personally identify with a candidate can see the candidate's bald-faced lies as "symbolic protests against a crooked establishment." Politics is a game of leverage, not truth.
At #UNGA there will be many populist demagogues who lie compulsively. But why do people like and vote for them. This fascinating study explains it.
So, what's the diff? Answer (from our work; , ): Flouting the norm of truth-telling works when his supporters perceive it as performance art-- where he's acting as their "authentic champion" by sticking it to the "establishment."