If these were common outcomes within a few years of a Parkinson's diagnosis I might agree. They are possible, but not likely, outcomes in that period of time. All sorts of bad outcomes are possible over the course of the next four years, whether or not an individual has Parkinson's. By that criteria, we shouldn't choose anyone for President, because something bad might befall them. If we have additional information that would indicate that an individual is a particularly high risk for a bad outcome, then I would agree, that we should not consider them. But that leaves us back in the realm that a specific condition seldom should be an automatic rule out, we need to look at the total burden of risk.