The stage is being set up for a musical performance by Sheile E + Family.
Castro tells the immigration story of his grandmother, saying, "Grandchildren of Americans who suffered in World War II internment camps — the same camps Donald Trump has defended — and grew up to be business owners, war heroes, and public servants.
Children of immigrants who have contributed to our country as doctors, police officers, and — guess what — impartial judges," he says.
The "impartial judges" reference brings laughs from the delegates. Trump accused a U.S.-born judge of Mexican heritage of not being impartial. The judge is hearing a case involving Trump University.
Another video takes on Donald Trump's refusal to release his tax returns, the first presidential nominee in 40 years not to do so.
Some delegates are gamely trying to dance to Sheile E's set.