Julián Castro

Julian Castro, former U.S. Secretary of Housing and Urban Development and candidate for the 2020 Democratic presidential nomination, speaks to the media at Saint Anselm College in Manchester, N.H. (AP Photo/Mary Schwalm, File)

Julián Castro served as the U.S. secretary of housing and urban development during the Obama administration. He also served as mayor of San Antonio for five years.

The Democratic candidate for president announced he was running on Jan. 12. His campaign has emphasized a platform of universal prekindergarten, "Medicare for all" and immigration reform.

Castro, now 44, was mentioned as a possible running mate for Hillary Clinton during the 2016 presidential campaign. He is the twin brother of Congressman Joaquin Castro. If elected Castro would become the first Hispanic and Latino American president of the United States, as well as the first president whose highest experience was as a cabinet secretary since former President Herbert Hoover.

Castro was raised on the West Side of San Antonio, where his mother was the first Chicana to run for San Antonio city council. His initiatives as HUD secretary included efforts to make housing more accessible, reducing homelessness among veterans and offering internet access to families in public housing. As a candidate for president, Castro says he'll work to reduce college debt.