– Sen. Al Franken urged comedian and talk-show host David Letterman to run for U.S. Senate on Wednesday, according to excerpts released by CBS ahead of the telecast.

In the senator's first appearance on the "Late Show" since he first was elected in 2008, Franken talked about the controversy in Indiana surrounding a newly passed law, signed by the Republican governor, which critics say allows people or businesses to discriminate, or refuse to serve, individuals because they're gay.

Letterman, an Indiana native, said he was distressed about the news and asked Franken what he could do to make the current governor, Mike Pence, "uncomfortable."

"As a matter of fact, there's an open seat there," Franken said, noting that Republican Sen. Dan Coats is not running again. "Look … when people come to me, young people, they say how do I become a United States senator? And I say, well, do 35 or 40 years of comedy and run for the Senate. You know, it's worked every time."

Franken said what was happening in Indiana was a "disgrace."

"A lot of this is about the fact that in 1964 we sort of settled the idea that you had to serve people even if you were biased in some way," he said.

Franken was last on Letterman in 2008 ahead of his divisive election where he won by only 312 votes.

In the 1980s and 1990s, though, he was on dozens of times. He and Letterman are old friends from his days as a writer on "Saturday Night Live." Letterman's last show is in May.