A large percentage of people genuinely buy into the "just world" fallacy, regardless of whether they consciously recognize this. They believe that if someone is in a position of power, they deserve to have that power.
Of course, many of them also believe that, variously, the world is inherently just, people are inherently good, or the world's structure is ordained by a loving God. Therefore, these people deserving power isn't just Fated, it's also because they're better people. Smarter, better leaders, possessed of the qualities that fit one to rule.
Therefore, "the people in power are smart, have the best interests of the many at heart, and are worth listening to" is effectively axiomatic for a great many people in our society.