Dee ihe ọzọ maka paragraf a - N'afọ 2008, Díaz ghọrọ onyeisi oche nke U.S. Conference of Mayors. Dịka onye nweere onwe ya, na onye bụbu onye Democrat edebanyere aha, Diaz kwuru okwu na 2008 Democratic National Convention ma kwado Obama na-achọ ịbụ onye isi ala
Ọ dị mma. Mgbe ntuliaka Obama gasịrị, a tụlere Diaz maka HHS Secretary; ọnọdụ ahụ ga-emesị gaa Kathleen Sebelius.