2 - Castro lost his first bid for mayor of San Antonio, but ran again in 2009 and won with 56 percent of the vote. He was re-elected in 2011 by an 82 percent margin.
3 - Castro rose to national prominence in 2012 when he became the first Hispanic to deliver a keynote address at the Democratic National Convention.
4 - Castro has a twin brother who is also a politician. Joaquín Castro has represented Texas’ 20th congressional district since 2013.
5 - Castro, who was born in San Antonio on Sept. 16, 1974, is graduate of Stanford University and Harvard Law School. He married Erica Lira Castro in 2007.
6 – Castro formed an exploratory committee for a possible 2020 run for U.S. president.