The purpose of this political system is to put people like Trump in power. We can infer this because it keeps putting people like Trump in power and yet nobody has changed it yet.

Look up the history of the phrase "the purpose of a system is what it does". It was adopted as a principle because it made more sense than every other possible alternative. It makes no sense to claim that the purpose of a system is to do something that it never has done and consistently fails to do, because the system would have been replaced in that case.