Louis C.K.’s new Netflix special 2017, filmed one week before Inauguration Day in Washington D.C., does not contain one joke about Donald Trump. When the comedian appeared on The Tonight Show last week, Jimmy Fallon declined bringing up the president’s name.

But Stephen Colbert was not going to let C.K. go without getting his latest thoughts on the man he once called “Hitler” and an “insane bigot” in a letter to his fans.

It took him until their second segment together to broach the topic, but Colbert wanted to know why C.K. has since said he “regrets” making those scathing comments about the man who would go on to win the 2016 presidential election.

“I don’t take it back, I regret it. There’s a difference,” C.K. said. “I regret saying it. It doesn’t mean it’s not true. It’s a messy thing, you know, it’s how I was feeling at the time. And I said it to a lot of people. It just was more people than I thought were going to read it.”

Now, C.K. said he has realized Trump is not as “profound” as he once thought he was. “I thought he was some new kind of evil. But he’s just a lying sack of shit.”

Using his unique gift for language, C.K. explained to Colbert the difference between someone who has lied before, a person who “lies once in a while,” who can’t quite stay within the bounds of truth, and a straight-up “liar.” Then, he said, you have “lying sacks of shit” like President Donald Trump.

“He likes it!” C.K. said, imitating Trump laughing as he tweets and saying, “‘It wasn’t even true! And then I said they were liars!’”

“He’s just a gross, crook, dirty, rotten, lying sack of shit,” he continued to cheers from the audience before acknowledging, “And that’s not a courageous position in this room.”

To possibly the one Trump voter in Colbert’s crowd, C.K. said, “He’s the victim of the lying. That’s the guy he lied to. He didn’t lie to me. Everybody else was like, ‘Yeah, no, that’s not true.’ But that guy bought it.”

“It’s not a political position,” C.K. clarified. “It’s just when you look at someone you go, that guy’s a lying sack of shit.”

Colbert said he found it “refreshing, in a way, to see somebody who lies so much,” to which C.K. responded, “I don’t think his name is Donald Trump.” (As John Oliver informed us more than a year ago, his family’s real name is Drumpf.)

“Don’t you want God to show up and say, I was just kidding, about everything?” C.K. asked. “I just wish that he would.” The “good news,” he added, is that Trump is just “one guy.” But “on the flipside,” as “wonderful” as C.K. thought President Obama was, “half of Chicago shot the other half of Chicago while he was president and we bombed a bunch of weddings in Yemen.”

“I wish people would show up and do something,” he continued. And to the people who didn’t vote, who didn’t like Hillary Clinton, C.K. said, “They didn’t even show up to give him an opposite Congress, they didn’t even show up for that, they just didn’t want to.”

“But voting isn’t something you do because you want to. You don’t look at it like, what do I want, what do I feel?” he said. Instead, he explained, people should be asking themselves, “What will happen if I don’t?”

“That’s called being an adult,” C.K. said.