This umpteenth season is very slowly announcing our newest idol--a woman: probably a woman named Kree.
The show American Idol puts contestants through a few rounds of singing talent and performance competitions. Then the finale crowns a winner--presumably, the best talent and performer who is an American idol. Whether you are watching from the show's judge's panel or from home, you judge the contestant, their talent, their look.

The believability is an extension of the theater of the show--the anticipation, the suspense, the competition, the deployment of sincerity, pain, disadvantage (as advantage), hopes, and dreams and effort. As theater, the contestant has her part, and the momentum of the show's theatricality inevitably leads to a climax demanding the idol be selected.
The selected contestant, the winner, is an idol before she even wins. She is merely crowned by the finale. The judges often claim that this is "a singing competition". No, it certainly isn't that simple. And that the show employs a democratic element makes no difference at all.
Notes:
Nicki Minaj is probably a better judge than she's given credit for being. Unless she is given a lot of credit for this. I wouldn't really know.