... long before he ever ran for President. As I understand it, according to Johnston and others, Chump would waste massive amounts of time obsessing over "carpets and drapes" and other tiny details of his hotels ... but meanwhile he was defaulting on major stuff like making sure the employees got paid and the doors stayed open.
Chump was never a micro-manager, he was just too lazy to put the time in on actually managing his businesses. Aways it was someone else's job to handle the important stuff, and most of them including his own brother were fired for petty and unfair reasons. The few who didn't get fired were people who knew how to play his games and stay on his good side.
Of course we all know that "The Art of the Deal" was a load of hogwash, and Chump never wrote an actual word of that book or any other. The ghost author Tony Schwartz has already blown the lid off that story.
From what we've heard about Chump's first term in the White House, we know that he didn't do much actual "work" as President, other than show up for the TV cameras and sign blank sheets of paper that he pretended were bills. People like Peter Navarro and Stephen Miller (and others) made up for the huge deficits in Chump's management style.
It's quite possible that the dementia and sundowning was going on during his first term, and the White House staffers did a good job of hiding it from the press. OR maybe this term the media is actually doing its job (finally) by reporting how bad it really is.