Late Show host Stephen Colbert offered a bluntly negative assessment of a potential Donald Trump presidency in an interview with BuzzFeed News on Friday, saying he's worried by the notion of a president who changes his positions constantly.

"I think it would be bad," Colbert told BuzzFeed Editor-in-Chief Ben Smith. "I don't think I have to be fair or balanced about that. I don't think he's a serious person. He's serious in his candidacy, and I'm sure he'll surround himself with good people or intelligent people who understands how the government works, or something like foreign policy, something like that.

"It worries me that someone who can change their position so much might be in the White House. He seems essentially emotional rather than thoughtful."

The late-night comedian added that he's looking for some sort of consistency out of Trump at next week's Republican National Convention, saying he wants to call "no fair changies" on Trump. "Whatever policy gets stated, whatever somebody says on the stage, you have to live by it on Wednesday, so by the end of the week, we've built some sense. And if that happens, I'd much more comfortable with him being president of the United States," he said, adding that he suspects whatever gets said next week "won't mean anything."

Colbert also commented on Hillary Clinton's efforts to appeal to younger audience, sarcastically describing them as "flawless."

"They're dope, yo," Colbert joked. "They're Pokémon Go, yo. I'm not just a grandma, I'm an insta-grandma. Hashtag Snapchat." Colbert said the only thing Clinton can do is "own the fact that she's making lame jokes."

"I think she thinks it's working. That's the adorable part. She thinks it's working," Colbert concluded.