Julian and Joaquin Castro Weigh In on Hillary Clinton, Donald Trump

The twin brothers said Clinton should "be herself" during her address tonight.

"I'd be lying to you if I said there wasn't a little bit of a disappointment," he said, "but I also know that I'm 41 years old and that God willing, I'm going to have a lot of years left and I know that I got into public service because I felt very blessed with opportunity...Whether I'm in the public sector or the private sector, I'm going to find ways to create more opportunities."

Julian Castro said further that Clinton had made an "excellent choice" with Kaine.

"He is well-prepared. He has been a governor, a senator. He understands the world," Castro said. "He's a great choice for VP."

Rep. Castro, who represents San Antonio in Congress and was scheduled to speak today at the convention, shared with Muir some of what he planned to say.

"I'm going to call him out, yeah, directly," he said. "There is a lot of frustration and anxiety in the country but as an elected official and as a politician, you can direct that energy in different ways and he's directed it in a very divisive and negative way and really played on people's fears and resentments."

"This election truly is about a choice we're making between a candidate in Hillary Clinton that has a broad inclusive view of America and in Donald trump someone that has a darker sort of exclusive view of America," Julian Castro said.