Dana Carvey is finally dishing on how he spent two years developing his Saturday Night Live impersonation of former U.S. President Joe Biden – especially after he began showing “obvious” signs of cognitive decline during his presidential campaign.

Modern Family actress Julie Bowen was visiting Carvey and David Spade‘s Fly on the Wall podcast when she asked Carvey if his impersonation was impacted by Biden’s “severely diminished” cognitive health.

“I knew that he was compromised mentally,” Carvey admitted. “I mean, it was obvious to me, but it was a delicate thing in the comedy world. There were a lot of people did not want to do anything that would kind of ding him in like an awkward way.”

Bowen then pointed out, “But it’s comedy!”

“That’s it. That’s the key,” Carvey replied. “If I can do Biden, if I can make Biden funny to everybody, then, then I am where I want to be. And then to make it funny, it had to be recognizable. And so there’s certain things I did not include in my package.”

He then did an impersonation of Biden firing off a string of incoherent sentences. “Ladies and gentlemen, the leader of the free world,” he joked.

Spade also pointed out, “I think it’s easier to make fun of him if he’s the president. If it’s just a 90-whatever-year-old man, just go look at this asshole. So once he’s president then he’s more fair game to say, but no one made fun of him forever.”

Carvey said it took him two years to perfect the impersonation.

“The first six months it was just sweet Joe … it was just that it doesn’t have the proper energy of Trump, or even Obama, or [George W. Bush],” Carvey said. But his impersonation of Biden eventually became his “favorite.”

Carvey’s notable performance as Biden was submitted for Emmy consideration for the category of Outstanding Guest Actor/Actress in a Comedy Series.

Even Biden’s staff were fans of his impersonation. The comedian revealed that he met some of Biden’s staff at a party, where they invited him to visit the White House but “it never happened.”