Medical professionals determine who the mentally defective are by psychological tests and observation of behavior. But there is a much easier and less time-consuming way to make this determination.
Simply ask them if they support Hillary.
If they do, then the diagnosis of mental impairment is abundantly obvious. And if so, confinement to an institution should be mandatory. For such individuals to remain in society poses various threats to the public at large.
Who knows what they might do next? We all know the unbalanced are unpredictable