I don't see how beneficial utility of a $350M plane, no matter how temporary, isn't emoluments. Perhaps running the system makes it legitimate no matter how lawless.
Usually when cognitive decline causes someone to become this kind of a wild liability, their kids reluctantly have "the conversation" and take away their car keys. But no, someone gave this demented maniac a soap box instead, and his ramblings were able to rile up enough like-minded entitled and indignant followers for him to get given even greater authority. Now his decline is our decline.
Americans, on paper, don't elect dictators for 4 years. While they may elect people who either misinterpret the scope of Article II or listen to others who do, this is not solely the fault of the foundational documents and intents.