Republican Geoff Duncan made reference to the aftermath of the 2020 election in his remarks, noting that his path to the DNC podium began when Trump tried to overturn his election loss to President Biden in Georgia.

A video is now airing of Trump's remarks on Jan. 6 at his speech at the Ellipse, as well as footage of rioters breaching the Capitol.

Coming on stage soon is Rep. Bennie Thompson, the chairman of the House Jan. 6 Committee, which after a yearlong investigation recommended the Justice Department bring criminal charges against Trump over the Capitol attack.

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."