Joe Scarborough's conjecture about whether 45 can read is an interesting issue to ponder. Consider: 45 has an MBA from Wharton if I recall correctly. He also writes an amazing number of Tweets for a man of such a high position. (These are not, so far as I can tell, ghost-written, unlike his books. See Tony Schwartz about the ghost-writing one of 45's books.) So, what has happened to 45's presumed ability to read? On one hand, it could be a lack of capability. That is, his mental illness--whatever we may label it (and yes, I'm presuming his "diagnosable")-- may include some organic components that limit his ability to focus sufficiently to read anything of any substance. Bad.
But the other possibility, perhaps in tandem with the organic theory, is that 45 doesn't believe that he needs to read. He already knows it all. And for all his failings, as one friend of mine described him, he is a "man of low cunning." Perhaps for a long time now in his career, he's gotten by strictly with the spoken word. He is a cave man not only in demeanor but in language as well. His lack of knowledge and sophistication are traits that he's cultivated to his advantage thus far in his life. He didn't expect to become president, he only expected to gain publicity for what was--and continues to be in his mind--a publicity stunt. He has been astonished that someone would want him to master new information when all he wants to do is practice his art (one-off salesmanship). A con artist doesn't need to read memos, he needs to talk it up. He doesn't need to learn what other thinks, he need only talk the mark into doing his bidding.
Of course, we've had presidents before who were not mental giants. But 45 takes us into completely uncharted territory. He is a cultural regression from the era of the written word back to the time before writing. For Trump, literacy is of limited value and orality is king. (What what would Walter Ong and Marshall McLuhan say about all of this?) Of course, 45's orality is only partial because he does Tweet, and he can read a text prepared for him. But in crucial ways, he represents a fundamental regression and a path back into the darkness for those who would follow his lead.
Beware, my friends.