The decision by the Senate's highest-ranking Democrat to stay quiet about Franken's latest accuser is particularly notable given recent heightened sensitives about sexual harassment allegations and fresh calls for resignation on Thursday from some of Franken's Democratic colleagues.
It comes after CNN reported Thursday morning of a fifth woman to accuse Franken, a Minnesota Democrat, of having groped her years ago. Stephanie Kemplin, a 41-year-old Army veteran of Maineville, Ohio, said she met Fraken while she was deployed in Kuwait in December 2003. Franken, who was not in office at the time, was visiting as part of a USO tour.
As the two were posing for the photo, Kemplin said, Franken put his hand on her breast.
"When he put his arm around me, he groped my right breast. He kept his hand all the way over on my breast," Kemplin said in an interview. "I've never had a man put their arm around me and then cup my breast. So he was holding my breast on the side."
Kemplin said she did not say anything to Franken in the moment. CNN spoke with Kemplin's sister and an ex-boyfriend, who said Kemplin told them about the encounter at the time.
House Democratic Caucus Leader Joe Crowley of New York said in a statement to CNN that he believes both Franken and Democratic Rep. John Conyers of Michigan, who has also come under sexual harassment allegations, should both resign.
"Congressman Conyers and Sen. Franken should do the right thing for the country, the institution, and, most importantly, the women involved, and resign," Crowley said.
Democratic Rep. Tim Ryan of Ohio wrote on Twitter: "I agree with (House Minority Leader Nancy) Pelosi. Conyers should resign. And for that matter, Franken should resign too. These are credible allegations, and I believe these women. Congress should set the example for all industries and be a safe place for women to work."
Franken told local media outlets over the weekend that he had no plans to resign.
Kemplin is the fifth woman in two weeks to accuse Franken of inappropriate touching, and the second person to allege that such misconduct took place while Franken was on a USO tour. Three of the five women have been identified by name.
Meanwhile, the Senate Ethics Committee made the rare move of publicly announcing Thursday afternoon that it has launched a preliminary investigation into Franken's alleged misconduct.
Democratic Sen. Patty Murray of Washington told CNN Thursday morning: "We have to take allegations seriously and like I said before, he needs an ethics investigation and I believe that."