The incident was one of many fiery exchanges on Thursday's episode of the ABC show, where Trump clashed with the liberal hosts, including Whoopi Goldberg and Joy Behar. But with McCain, the daughter of the late anti-Trump Republican Sen. John McCain, and the show's conservative, on the attack, Trump had no respite from criticism.
"A lot of Americans in politics miss character and a lot of people miss the soul of this country. You and your family have hurt a lot of people and put a lot of people through a lot of pain ... Does all of this make you feel good?" McCain asked Trump on Thursday's show.
McCain specifically pointed to the Khans, a gold star family who criticized then-candidate Donald Trump during the 2016 election.
"I don't think any of that makes me feel good," Trump Jr. said, "but I do think that we got into this because we want to do what's right for America. My father has been working tirelessly to bring back the American dream."
He added that his father brought jobs back to the United States and drastically lowered unemployment numbers for African Americans. Co-host Whoopi Goldberg balked at that claim, saying that it wasn't "fact."
"I understand that he is controversial. I understand that he has offended a lot of people but I also understand that he took on the establishment and that's the premiere sin in American politics these days," Trump Jr. added.
McCain followed by asking Trump Jr. whether he felt it was "worth it" to put gold star families through "pain."
John McCain often criticized Trump's conduct, and President Trump, in turn, frequently attacked the former Navy officer and Vietnam prisoner of war.
When co-host Sunny Hostin mentioned that the president attacked McCain's father, Trump Jr. apologized. "I understand that and I'm sorry about that and they did have differences," he said.