President Trump reportedly called Angela Merkel "stupid."
Mr Trump, 74, allegedly called Angela Merkel, the German chancellor, “stupid” and Theresa May “a fool” over Brexit, officials told CNN.
(The Times, "Delusional Trump called Merkel stupid, officials claim", July 1, 2020)
Quite the contrary, Angela Merkel earned a doctorate in quantum chemistry in 1986 (source), and is arguably not stupid. For the purpose of this question, let us assume that Trump is stupid, but is not aware of this.
Is there an idiom or phrase for someone misapplying an attribute to someone else, while the speaker should have more aptly apply it to himself? (I'm looking for an idiom or metaphor that an observer could apply to the speaker.)
"Although Trump called Merkel 'stupid', it seems to be an instance of __________"
"When I was in Africa, a street urchin called a better off African 'poor.' This is a great example of _________."
Idioms and phrases that are close
The idiom The Pot Calling the Kettle Black would apply only if both Trump and Merkel were stupid.
The psychological term displacement includes
A characteristic that one perceives in oneself but seems unacceptable is instead attributed to another person. This is essentially the mechanism of psychological projection.
For displacement to apply, Trump must perceive that he is stupid.
The psychological term delusional is what The Times applied.
A delusion is a belief that is clearly false and that indicates an abnormality in the affected person’s content of thought.... The key feature of a delusion is the degree to which the person is convinced that the belief is true.
Delusion is a good word, a strong word, but it only goes one direction (namely his belief about Merkel). It does not address whether Trump mistakenly thinks he is smarter than Merkel.