Jimmy Fallon, are you listening?

The way late-night hosts treat Donald Trump became a hot-button issue after Jimmy Fallon's interview with Trump on the Tonight Show, where he drew criticism for going too easy on the Republican presidential candidate.

David Letterman has excluded himself from that narrative since leaving the Late Show last year. Until now, where he describes how he'd face off in the host's chair against Trump in a New York Times interview.

Responding to a question about his approach vs. Jimmy Fallon's more positively-spun interview, Letterman had strong words. "If I had a show, I would have gone right after him," he said. "I would have said something like, 'Hey, nice to see you. Now, let me ask you: what gives you the right to make fun of a human who is less fortunate, physically, than you are?'"

"And maybe that’s where it would have ended," he continued, explaining that he wouldn't be interested in going tit-for-tat with Trump on policy issues. "But if you see somebody who’s not behaving like any other human you’ve known, that means something. They need an appointment with a psychiatrist. They need a diagnosis and they need a prescription."

Letterman, no stranger to hosting Trump on his show, also told the NYT that the Donald was the "perfect guest."

"I would make fun of his hair, I would call him a slumlord, I would make fun of his ties," he said. "And he could just take a punch like nothing."

In fact, Hillary Clinton even used a 2012 clip of the host mocking Trump for outsourcing the production of his Macy's clothing line in a campaign ad.

Letterman was pleased Clinton included his interview in the ad. "I was flattered," he said. "I was pleased. I felt like I still have a small voice in this. I thought it was good."