Much of Monday's program appeared aimed at giving Sanders' backers an opportunity to express their frustration before the convention moved on to focus on speakers who strongly support Clinton, such as first lady Michelle Obama. Tim Kaine, was a disappointment and that he would have preferred Massachusetts Sen.
Huckabee also says he's gotten to know Kaine personally, and he likes him because he is "a genuine guy" and "an honourable guy".
A leftwing firebrand particularly popular with Sanders' supporters, Warren has taken on the role of attack dog against Republican presidential nominee Donald Trump. He also has experience as a civil rights lawyer, which has won the respect of many progressive voters in Virginia.
Kean, who chaired the federal 9/11 commission, skipped this year's Republican National Convention, the first time he's done that since he became involved in politics, because he disagreed with Trump on too many issues.
Clinton, 68, had said she wanted a running mate with enough experience to "literally get up one day and be the president of the United States".
Sanders' supporters were upset when Wikileaks released almost 20,000 emails to and from DNC staffers that call the presidential candidate a "damn liar" among other hostilities.
Clinton's running mate, the former DNC chairman, later chimed in with his take.
"I often feel like there's the Hillary standard and then there's the standard for everybody else", she said.
Kaine, a former Richmond mayor, was asked to join the choir and sing a solo just hours before the service. But he remains largely unknown on the national political stage. He introduced himself to the American public, switching between English and Spanish and talking about his time as a Catholic missionary in Honduras.
"Lin's still a Republican but he's voting for an bad lot of Democrats these days", said Kaine.
"Donald Trump may think America's in decline, but he's wrong".
But Clinton dodged the inquiry, claiming she "didn't know anything about it" and that she hadn't read "any of those emails".
Pelley pressed Clinton, saying, "They seem to have their thumb on the scale for you". "Bill built a bridge into the 21st century and Barack gave us hope". Elizabeth Warren, a favorite of liberals who has emerged as one of the Democrats' toughest critics of Trump.
Kaine recently contradicted previous statements he's made on trade by announcing that he opposes the Trans-Pacific Partnership, a massive trade deal with Asian countries favored by the Obama administration. "Let's be clear, Tim Kaine is definitely a liberal".
Kaine's allies say his record must be judged in totality.