On Sept. 29, 2001, less than three weeks after the 9/11 attacks, Saturday Night Live returned for its first new episode of the season. Seth Meyers and Amy Poehler had just been hired to join the cast, Tina Fey was serving as co-head writer, and Michael Schur had just been promoted to head of “Weekend Update.”

But instead of starting with a cold open comedy sketch, the lights came up on Mayor Rudy Giuliani, who was surrounded by a group of New York City police officers and firefighters. He delivered a heartfelt message of gratitude and resilience and then Paul Simon performed “The Boxer” wearing an FDNY hat. When Simon finished the song, SNL executive producer Lorne Michaels joined the mayor on stage and asked him, “Can we be funny?”

“Why start now?” Giuliani replied as the entire room and everyone watching at home let out a huge sigh of relief.

“Great joke, wonderful joke,” Schur recalls on this week’s episode of The Last Laugh podcast, before adding, “I don’t know what happened to that guy…”

Schur, who moved to New York to join SNL’s writing staff in the fall of 1998, says he “loved” Giuliani after 9/11. “He really was inspiring, the way that he was moving around the city and holding things together at a time when it felt like the whole world was falling apart,” he says. “I would have voted for Giuliani, happily, if he had run for mayor after that.”

“In the intervening years, he has lost his mind,” he continues. “But even though he is now a straight-up loon, I still can’t bring myself to retroactively be upset with him. Because at the time, the things he was doing for New York were so meaningful and made so many people feel safe and good. And I think the reason why is because it wasn’t political. And it was very comforting. So I can compartmentalize with that guy, even though now when I see him, I feel like I want to vomit.”

Schur, who went on to write for The Office before creating Parks and Recreation, Brooklyn Nine-Nine and The Good Place, describes SNL as being on the verge of an “upswing” when he started there under head writer Adam McKay. But things “really kicked into high gear” the following year when Will Ferrell started playing George W. Bush opposite Darrell Hammond’s Al Gore. “Suddenly, dumb sketches you wrote were being played on CNN,” he remembers.

There has long been a theory that Ferrell’s genial portrayal of Bush may have helped push him over the edge in the extremely narrow 2000 election. And Schur doesn’t dispute it. “Oh totally, 100 percent. It’s not even conjecture,” he says.

Jim Downey, whom Schur calls “the most famous and best writer at SNL in its history” and whom McKay has called a “right-winger,” wrote the three general election debate sketches that year, including the first one that coined the term “strategery” for Bush and depicted Gore as a wooden, boring technocrat who couldn’t stop sighing with frustration at his opponent’s apparent lack of knowledge.

“Gore’s staff showed him Downey’s sketch and told him, this is how you came across, you have to change,” Schur says. “And he came out in the next debate and was a lot more under control. Bush had been a moron in the first debate and for the second they had clearly drilled facts into his brain.”

Of course, SNL’s outsized influence on presidential politics may never have been felt more than in the fall of 2015 when Lorne Michaels invited Republican candidate Donald Trump to host.

“That was a critical error and many, many critical errors were made in 2016,” Schur says. “Because it wasn’t attacking him, it was tacitly endorsing his existence and normalizing his attitudes and behavior.” In his estimation, it was an attempt by Michaels to “stay relevant,” explaining, “Lorne likes it when the people who are being talked about in the culture come on the show.”

“ That was a critical error and many, many critical errors were made in 2016. Because it wasn’t attacking him, it was tacitly endorsing his existence and normalizing his attitudes and behavior. ” — Former ‘SNL’ writer Mike Schur on Donald Trump hosting the show

“I think most people were—and he was too—kind of blindsided by the fact that that can backfire,” he continues. “It’s never backfired like that before. It’s one thing when Nancy Kerrigan is attacked and then she hosts the show because everyone’s talking about Nancy Kerrigan. Trump was a different story and it was a mistake. No one would say it wasn’t a mistake to put him on the show as just another person who’s being talked about in the culture because that’s not what he was.”

From the day Trump announced his candidacy by calling Mexican immigrants “rapists,” Schur says that should have been “disqualifying” to host SNL. “If you’re that unreasonable of a person you don’t get to be part of our thing we’re doing here,” he says, calling the incident where Jimmy Fallon playfully messed up Trump’s hair on the Tonight Show a similar “mistake.”

But Schur makes sure to note that SNL and Fallon are not alone in making errors in judgement like these. He also faults Stephen Colbert for including Sean Spicer in his Emmy Awards monologue. “That was a mistake,” he says. “And when it happened, I was like, no, Stephen, what are you doing?

Over the years, former SNL cast members like Horatio Sanz and Taran Killam have openly criticized Lorne Michaels for either valuing political neutrality over hard-hitting satire, or in the case of Trump, being overly solicitous of the right. It’s a debate that was brought to the surface once more this past year after SNL hired and then fired comedian Shane Gillis in an apparent attempt to appeal to a more conservative audience.

And yet despite Schur’s ultra-progressive politics (see his @KenTremendous Twitter feed) he says that tension never caused issues for him during his time on the writing staff.

“Lorne’s attitude is, the show was forged in the boiling cauldron of Watergate and the attitude of the show is ‘we are skeptical of whoever’s in power.’ That’s the deal,” he says. “I have no problem with that as a philosophy. I think that part of what makes America America is that its art gets to take down its leaders. And it’s not hard to make fun of Democrats even if you happen to side with them politically.”

“Whatever the prevailing attitudes are, the show attacks those attitudes,” he adds, “and I think that is a good M.O. for a TV show.”

Bringing Trump on to host the show, however, was clearly a bridge too far.

“I think people were still running the old playbook, where, yes, they are extreme in their beliefs but it’s still OK to bring them into the tent and give them airtime because ultimately the country is reasonable and will see them for what they are,” Schur says. “But they just kept coming, they didn’t relent, it didn’t change their behavior. So what ended up happening is they got normalized. Their attitudes got normalized in a way I don’t think they should have.”

Next week on The Last Laugh podcast: Stand-up comedian Fortune Feimster, whose new Netflix special Sweet & Salty premieres Tuesday, Jan. 21.