San Antonio mayor Julián Castro will deliver the keynote address at the Democratic National Convention in September, becoming the first Latino elected official to get the coveted keynote speaker spot.

The choice both affirms Castro's status as a rising star in the party and signals Democrats' commitment to Latino voters, who turned out overwhelmingly for President Obama in 2008 and are poised to make a critical difference in several swing states.

The keynote address offers an opportunity to showcase promising young officials and present them to a nationally televised audience. A young Illinois state senator named Barack Obama have his political career a boost after he delivered an electrifying keynote address at the 2004 Democratic National Convention.

"Being the keynote speaker at the convention this year is an honor I don't take lightly," Castro said in a video announcement. "I know I've got some big shoes to fill," recalling how Obama's speech inspired him to continue pursuing public service.

Castro, the son of a Mexican-American activist prominent in the Chicano movement and a graduate of Harvard Law School, was elected mayor of San Antonio in 2009, at the age of 34. The New York Times magazine wrote a glowing profile of him in 2010 in which Mark McKinnon, a top Republican operative, said Castro "has a very good chance of becoming the first Hispanic president of the United States."