Query: Why did Richard Brodhead believe there were so many Yale alumni presidential candidates?
Context: Yale President Richard Levin attributes the run to Yale’s focus on creating "a laboratory for future leaders," an institutional priority that began during the tenure of Yale Presidents Alfred Whitney Griswold and Kingman Brewster. Richard H. Brodhead, former dean of Yale College and now president of Duke University, stated: "We do give very significant attention to orientation to the community in our admissions, and there is a very strong tradition of volunteerism at Yale." Yale historian Gaddis Smith notes "an ethos of organized activity" at Yale during the 20th century that led John Kerry to lead the Yale Political Union's Liberal Party, George Pataki the Conservative Party, and Joseph Lieberman to manage the Yale Daily News.