A core value in a democracy is an informed citizenry. In the contemporary era, candidates and office holders are expected to disclose critical information about their health and competency. Citizens have a right to any information that is relevant and meaningful for those in office or seeking office for positions of power that affect the general welfare. This would include, but not be limited to, considerations of dangerousness.
If a candidate for high office was diagnosed with an incurable neurological disease that affected his or her judgement, we would feel entitled to that knowledge. If a candidate was diagnosed with a life-threatening illness and thus not expected to survive his or her term in office, we would likewise feel entitled to that information. If a trained professional has determined that the President has a condition that conveys danger to others, he/she has a duty to inform.
See this article (https://journals.sagepub.com/doi/10.1177/1745691617727864) for a scholarly discussion of the ‘duty to inform’ principle.
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