There are times when presidents speak to the world and make history with commencement addresses. John F. Kennedy announcing the opening of test ban treaty talks at American University June 10, 1963. Lyndon B. Johnson proclaiming the Great Society at the University of Michigan May 22, 1964. Ronald Reagan rallying a generation and announcing the West will "transcend communism" as "some bizarre chapter in human history" at the University of Notre Dame May 17, 1981. Bill Clinton launching a "national conversation" about race at the University of California at San Diego June 14, 1997. And George W. Bush outlining the Bush Doctrine and telling the nation how he would conduct the war on terror at West Point June 1, 2002.
Then there are times when presidents speak to constituency groups and try to make political hay; times like Monday when President Obama addressed the graduates of Barnard College in New York City.