At the Democratic National Convention Tuesday, San Antonio Mayor Julian Castro was the first Latino ever to give the keynote speech at the convention. He's a rising star in the Democratic Party, and his speech hit Mitt Romney as hard as a man of privilege who doesn't understand the struggles of average Americans.

He was introduced by his identical twin brother, Texas state representative and U.S. Congressional candidate, Joaquin Castro. Both Castros talk to Soledad O'Brien on "Starting Point" this morning about the importance of the Latino vote.

"There's no question that the Latino community is absolutely important to the election," Mayor Castro says. "More importantly than that, the destiny of the Latino community is interwoven with the destiny of the United States. As you know, it's the fastest-growing community. It's a young community. When we think about the talent and the brain power that we need to keep America competitive in the 21st century global economy, the Latino community is a great reservoir for that. So, my keynote speech, I think, was one more signifier of how significant and important the Latino community is to the future of the United States."

Soledad asks them if it's hard to sell President Obama's message with unusually high unemployment numbers in the Latino community.

"I don't think it is a tough message for President Obama, because when they look at the progress that has been made, the Latino unemployment rate has dropped by about two percent under this president's watch...more than 150,000 Latinos now are able to get Pell Grants because of investments that the president pushed. Nine million Latinos are going to be able to avail themselves of good healthcare under the Affordable Care Act. For many Latinos, the emergency room literally is their primary care physician. So, that's a huge deal. On immigration policy, that's been talked about tremendously," he says.

"The president is the only one in Washington that's trying to do anything positive with his administrative decision on the dreamers and prioritizing deportations for criminals and then on tax policy," Mayor Castro adds.

Soledad also asks if they're worried about a bump in polls for GOP presidential nominee Mitt Romney with Latino voters after the Republican National Convention.

"I think some of it was exposure, because a lot of people still didn't know, including a lot of Latinos, who Mitt Romney is. But also, because they put their best face forward at that convention and didn't talk about a lot of the very extreme policies that many in the Republican Party are taking towards the Latino community," Joaquin says.