Donals Trump was under the impression that he’s in charge.
People do not get themselves elected, any more than they get themselves hired. The false attribution of agency is a logical flaw that, all too often, the popular press engages in.
Nevertheless, it creates a wrong impression of potency and responsibility and is akin to “blaming the victim,” another widespread habit. The purpose it serves is to disguise responsibility and, consequently, the ability to prevent a repetition effectively.
If one does not know who did something, it is not possible to stop them from doing it again. This is particularly detrimental in a society that is committed to responsive, rather than pre-emptive, law enforcement.
So, in a sense, the false attribution of agency serves to undermine the principle of “innocent until proven guilty.” If the guilty cannot be properly identified, then there is a temptation to impose universal restraints. There is no liberty when that happens.