There are at least two key things to realize here:
1) When people work massive hours on sleep deprivation, as the 60 year old Hillary has, they're likely to make some slips and gaffs. In fact, this is a big reason why candidates should think carefully about whether it's worth working that extra hour or two per day at the expense of less sleep. The same goes for people in many other important thinking professions. If you look at Hillary's lifetime of real giving, caring, and sacrificing for others, and the policies she advocates to help those less fortunate, even though she's been a member of the wealthy and powerful – real things not the superficial – then you realize that obviously things like Hillary's pointing out Robert Kennedy's assination in June were not because she's a bad person.
2) The more we judge candidates based on the superficial – instead of what they really advocate for the people, their policies (like Obama's Health care policy versus Hillary's), the caring they've shown in their actions and sacrifices – the more we will get good ol' boy act George W. Bushes, or just far worse politicians who do more bad and/or less good for ourselves and our families.