NEW YORK >> A conversation between two comedians turned serious today when U.S. Sen. Al Franken said “everything points to” collusion between President Donald Trump’s campaign and the Russians.

The Minnesota Democrat did not cite any evidence, noting a special counsel has been appointed to lead an FBI probe into the Republican administration’s ties to Russia. But Franken shared his “feeling” when pressed by late-night comedy legend David Letterman during joint appearance in New York City.

“My feeling is that there was some cooperation between the Trump campaign and the Russians. I think everything points to that,” Franken told Letterman, who moderated a discussion designed to highlight the release of Franken’s new memoir.

Franken added, “They just haven’t been acting like people who have nothing to hide.”

The Associated Press reported earlier in the day that Trump’s personal attorney, Michael Cohen, rejected a House intelligence committee request for information, while former National Security Adviser Michael Flynn will provide documents to the Senate intelligence committee as part of its probe into Russia’s meddling in the 2016 election.

Franken, a founding writer on “Saturday Night Live,” has emerged as a liberal hero of sorts during his two terms in the Senate. He insisted in recent days that he will not run for president in 2020, however.

“I see myself running for re-election in 2020,” he told Letterman of his plans to seek a third Senate term.

Letterman and Franken ignored comedian Kathy Griffin’s photo shoot in which she’s pictured holding what looks like Trump’s severed head.

While Griffin apologized for the image, the Republican National Committee singled out Franken for accepting political contributions exceeding $3,000 from Griffin in recent years. The two were scheduled to appear together at an event in California in the coming weeks.

Franken spokesman Michael Dale-Stein did not say whether Franken still planned to attend the event, but he condemned Griffin’s photo. The senator, Dale-Stein said, “believes this image was inappropriate and not the kind of thing that should be part of our national discourse.”

Back in New York, the comedians had the crowd roaring.

In classic deadpan style, Letterman drew a huge laugh when he declared, “I have begun to lose confidence in the Trump administration.”