I don't like Trump, and I rank his emission of word-shaped noises somewhere between picking random items from autocomplete suggestions, and my pre-ChatGPT experiments with GPT-3 models.
Charisma is a different axis to all of that.
A lot of people, for reasons I cannot even empathise with, demonstrably like him. One could even describe their response as "idolising" him. (Where does one draw the line between "a cult of personality" and "apotheosis" anyway?)
I work with a small university psychology department, and one of our recently-retired faculty made a several-decade study of charisma, particularly among political leaders.
Her primary theory is that it is built out of a combination of formidable and approachable traits/behaviors. Naturally, there is a fair amount of personal variability in what we perceive as "formidable" and "approachable", so what seems charismatic will vary from person to person; it's not fully objective.
But her theory is that this is why you can have people who are, objectively, more repugnant still read as charismatic, and people who are very pleasant read as less charismatic: the latter may be very approachable, but they don't have enough formidability to synthesize that into charisma, while the former add just enough approachability that they can.
Print out one of his speeches and read them. His success is built on backlash against the shock of seeing a black president.