Joaquin Castro Takes his Democratic Convention Turn

U.S. Rep. Joaquin Castro took the national stage Thursday on the closing day of the Democratic National Convention in the highest-profile speaking slot of the state's federal delegation.

U.S. Rep. Joaquin Castro, D-San Antonio, speaks to a group of Hillary Clinton supporters at a campaign event held at the home of Mark and Sharon Naughton in Iowa City on Aug. 30, 2015.

PHILADELPHIA — U.S. Rep. Joaquin Castro took the national stage Thursday on the closing day of the Democratic National Convention in the highest-profile speaking slot of the state's federal delegation.

The San Antonio Democrat took aim at Republican nominee Donald Trump's controversial statements on immigration, telling the crowd of his grandmother's immigration to Texas from Mexico.

"She wasn't a rapist or a murderer," he said. "She was a six-year-old orphan."

Describing the discrimination she faced and her difficult climb up the economic ladder, Castro said, "The fact that her grandson is standing on this stage tonight is proof that American kept its promise."

Grandchildren of immigrants grow up in the United States "to be business owners, war heroes and public servants ... doctors, police officers and — guess what? Even impartial judges," he said, in another implicit criticism of Trump.

Soon after securing the GOP nomination, Trump questioned whether a federal judge of Mexican descent could be impartial overseeing a lawsuit involving Trump's company. 

"The hero of that story is never the one who sides with hate," Castro said. "The hero of that story will never be Donald Trump."

The evening marked a particular historical significance: Clinton becomes the first woman to accept a major party's nomination for the presidency of the United States.

Castro's twin brother, Julián, delivered the keynote address at the 2012 Democratic National Committee Convention and was in consideration to be Clinton's vice presidential pick before she ultimately chose U.S. Sen. Tim Kaine of Virginia.