In his closing passage, Obama evoked John F. Kennedy, who had stood at this same university fifty years earlier and inspired what would become the Peace Corps. Kennedy had challenged students with a question: would a free society prove it could compete? Obama picked up that thread, reminding the graduates that everything they took for granted — free speech, the right to choose and criticize leaders, the chance to get an education — had been earned by previous generations through toil and sacrifice. None of it was preordained, and none of it was guaranteed to last. The task of keeping democracy alive was now in their hands.