It is when there is a human element to his presidency that Barack Obama tends to stand the tallest. And on Wednesday evening, as he spoke to 20,000-plus at a memorial service at the University of Arizona, there was, if nothing else, an emotional honesty to what he had to say. To a nation looking for clarity, Obama didn't pretend to have all the answers. There is, he noted, a tendency to demand "order" from "chaos," to try and "make sense out of that which seems senseless." Life doesn't always comply.