Walz introduced himself to the country and touted his accomplishments.
The third night of the Democratic National Convention continued the themes of joy and freedom.
A who's who of speakers, including a surprise speech from Oprah Winfrey, headlined the night aimed to showcase vice presidential nominee Minnesota Gov. Tim Walz.
"Coach Walz" brought his energy to the crowd touting his and Vice President Kamala Harris' vision for the future of the country.
Oprah Winfrey will be on stage at the Democratic National Convention on Wednesday night, multiple sources familiar with the program confirmed to ABC News.
CNN first reported the development.
--ABC News' Will Steakin and Katherine Faulders
Former Georgia Lt. Gov. Geoff Duncan, another Republican endorsement for Harris scheduled during the DNC this week, said Trump is a "direct threat to democracy."
"The only thing left to do is dump Trump," he said, as the crowd chanted "dump Trump."
Olivia Troye, a former Trump White House National Security official, told the crowd that "being inside Trump's White House was terrifying."
"But what keeps me up at night is what will happen if he gets back here," she continued.
She said she is proud to support Harris because they agree on the most important issue -- "protecting our freedom."
Democrats are trying to make progress with voters when it comes to immigration and border security.
A recent ABC News poll found Donald Trump retains the upper hand on the issue, keeping the race a closely contested one.
Trump leads Harris by 10 points in trust to handle the immigration situation at the U.S.-Mexico border, though he had led by 14 points in July.
Texas sheriff: Trump 'made our jobs harder'
At the DNC, speakers are bashing Trump for encouraging congressional Republicans to kill the bipartisan border deal negotiated earlier this year.
"He is a self-serving man," Javier Salazar, the sheriff of Bexar County, Texas, just said on stage. "Just like when he killed the border bill, he just made our jobs harder."
