One of the critics at the event asked the stars "is there evil," to which Harper quickly replied, "Yes. Our 45th president," reports Deadline.
Harper hosts HLN's How It Really Happened With Hill Harper, which launched in 2017 with an episode on the Melendez Brothers. Other episodes have centered on Jodi Arias, Aaron Hernandez, Ted Bundy, Casey Anthony, Gianni Versace, Chandra Levy and the deaths of musicians Prince and Michael Jackson.
"I couldn't be more proud of this project," Harper told the Atlanta Journal-Constitution about the series in 2017. "I've always been interested in telling stories. They've covered all these stories the past three decades."
Harper, who was a vocal supporter of President Barack Obama, has criticized Trump in the past.
"I would suggest to you fellow activists that we have been bereft in living with too little energy and taking what I would call the easy way out, allowing other people with antithetical agendas to out-energy us," he said at the University of Michigan's Rev. Martin Luther King Jr. symposium in January 2018, reports MLive. "One thing that you can say about Trump is that he brings energy. "
Harper continued, "What I believe (Trump realized) is that if he said it with enough energy and kept at it long enough, that he could actually sell a lie. And not only sell a lie, he could actually get other people to join a movement around a lie. What he's been able to do is take that same notion and out-energy us - shout it louder, say it stronger, keep at it, keep doing it, double down."
Harper is best known for his role on CBS' CSI: NY as Sheldon Hawkes. He now stars as Dr. Marcus Andrews on ABC's The Good Doctor, opposite Freddie Highmore.
In the next episode of The Good Doctor, producer Daniel Dae Kim makes his on-screen debut as Dr. Jackson Han, the new chief of surgery at St. Bonaventure Hospital. Dr. Han surprises everyone by considering Highmore's Dr. Shaun Murphy more of a liability than an asset.
The Good Doctor airs on Mondays at 10 p.m. ET on ABC.
Photo credit: Charley Gallay/Getty Images for Turner