Julian Castro says fresh candidates "cathartic" after what Democrats went through in 2016
Former San Antonio Mayor Julian Castro emerged on the national political stage when he delivered the keynote speech at the 2012 Democratic Convention. He went on to serve as U.S. Secretary of Housing and Urban Development under President Obama. Castro, who's considered a rising star in the Democratic Party, shares his life story in a new memoir called "An Unlikely Journey: Waking Up from My American Dream." Castro joins "CBS This Morning" to discuss his "likely" presidential run in 2020.