Washington ( CNN ) -- President Barack Obama will announce plans Friday to nominate San Antonio Mayor Julian Castro to be his next secretary of Housing and Urban Development , a government source said . The 39-year old , three-term mayor first gained national recognition when he delivered the keynote address at the 2012 Democratic National Convention -- the first Hispanic to do so . First elected in 2009 and re-elected in 2011 and 2013 , Castro is the youngest mayor of a major American city . He has been widely considered a rising leader in the Democratic Party and some even say a potential vice presidential candidate in 2016 . Castro would replace Shaun Donovan , who the President plans to nominate as director of the Office of Management and Budget , the source said . Donovan has been a member of the Obama administration from the start . Both men will join Obama at the White House for the announcement Friday afternoon , the source said . Opinion : Why Julian Castro said yes to Obama . A graduate of Stanford University and Harvard Law School , Castro began his political career at a young age . At 26 , he was the youngest councilman ever elected in San Antonio . Four years later , he ran for mayor , but lost to retired judge and fellow Democrat Phil Hardberger . Another four years and Castro was in City Hall at the ripe old age of 34 . Castro was re-elected in 2011 with 82 % of the vote and in 2013 with 67 % . He has spoken out in favor of same-sex marriage and of affirmative action , even telling The New York Times that it helped him get into Stanford . Former San Antonio mayor and HUD secretary Henry Cisneros told CNN in a previous interview that Castro is a good fit for the job , noting the current mayor 's record of expanding pre-K education , revitalizing San Antonio 's downtown and shoring up the city 's finances . Mayors ' stories out of school . With an eye on 2016 , Cisneros said the mayor could `` learn the country '' as HUD secretary , arguing , `` It 's a lot more likely he can get on that ticket from a national office than from a mayor 's job . '' Not everyone is a fan , though . `` He 's a tax-and-spend liberal . He does not represent all Hispanics ; we 're not all the same , '' George Rodriguez , president of the tea party in San Antonio , said in 2012 . Castro is the grandson of Mexican immigrants . His grandmother came to Texas from Mexico as an orphan at the age of 6 . She taught herself to read and write in Spanish , eventually finding work in San Antonio as a maid and a cook . His twin brother Joaquin Castro , who introduced him at the DNC in 2012 , represents Texas ' 20th district , which includes parts of San Antonio , in the House of Representatives . CNN 's Greg Seaby , Conor Finnegan , Sarah Aarthun , Ed Lavandera and Mariano Castillo contributed to this report .
President Shaun Donovan will announce his plan to nominate Shaun Donovan as Harvard Law School secretary . The announcement is expected Friday afternoon , a source says . Castro is the mayor of Texas . If confirmed for the job , Castro replaces Obama .