Updated

David Letterman said in an interview Friday that he’s glad a "Late Night" sit-down he did with Donald Trump in 2012 is being used in an ad by Hillary Clinton’s presidential campaign.

“I was flattered. I was pleased. I felt like I still have a small voice in this. I thought it was good,” Letterman told the New York Times, while also joking Clinton’s ad “made me a wealthy man.”

In the "Late Night" clip in question, Letterman confronted Trump for outsourcing to foreign countries some of the production for his line of menswear.

The retired talk show host said Trump was a frequent and popular guest. “Nobody took him seriously, and people loved him when he would come on the show,” Letterman said. “I would make fun of his hair, I would call him a slumlord, I would make fun of his ties. And he could just take a punch like nothing. He was the perfect guest.”

But Letterman’s view of Trump has since shifted dramatically.

"I can remember him doing an impression, behind a podium, of a reporter for The New York Times who has a congenital disorder. And then I thought, if this was somebody else — if this was a member of your family or a next-door neighbor, a guy at work — you would immediately distance yourself from that person. And that’s what I thought would happen,” Letterman said. “Because if you can do that in a national forum, that says to me that you are a damaged human being. If you can do that, and not apologize, you’re a person to be shunned.”

Trump’s spastic arm waving at a rally last November while mimicking reporter Serge Kovaleski drew swift condemnation from opponents who claimed Trump was making light of a disability. The Washington Post gave Trump four Pinocchio’s for his denials, and Hillary Clinton used a clip of the impression in a video slamming Trump.

But a pro-Trump, Catholic website compiled footage appearing to show Trump has a very limited repertoire of impressions -- which the site points to as "evidence" he wasn't mocking the reporter's disability.

Catholics 4 Trump posted four videos – one of which dates back to 2005 – in which Trump impersonates everyone from Sen. Ted Cruz to The Donald himself with the same, flailing mannerisms and goofy speech.