The Minnesota Democrat announced his resignation in a speech on the Senate floor.
Al Franken announced he is resigning from the Senate in the next few weeks, during a speech Thursday.
The announcement comes a day after Democratic women in the Senate led calls for his resignation following multiple allegations of sexual misconduct.
"We must lead by example," Washington's Patty Murray said in a statement. After half a dozen women called on Franken to step down, dozens of other Democrats followed, including Minority Leader Chuck Schumer and Democratic National Committee chair Tom Perez.
In a deeply cynical move, Majority Leader Mitch McConnell also demanded Franken's resignation — even as he has renewed his support for alleged child molester Roy Moore in the Alabama Senate race. The Republican Party, at the behest of admitted sexual predator Donald Trump, officially re-endorsed Moore earlier this week.
As Shareblue Media Executive Editor Jess McIntosh said on MSNBC Wednesday, "Your party is rooting for a pedophile. I think they’ve lost the moral high ground of any fight that they could possibly want to wage at this point."
During his Senate floor speech, Franken said he was proud to have used his time in the Senate "to be a champion for a women."
He then announced he will be leaving the Senate in the next few weeks.
"I may be resigning my seat, but I am not giving up my voice," he continued. "Minnesotans deserve a senator who can focus with all her energy on the challenges they face every day."
Franken also noted the "irony" of his resignation as the GOP rallies around an alleged child molester and "a man who has bragged on tape about his history of sexual assault sits in the Oval Office."
Franken thanked his Minnesota colleague, Amy Klobuchar, and the staff and activists who have supported him.
"I have faith in the proud legacy of progressive advocacy that I have had the privilege to be part of," he added.
Franken was elected to the Senate in 2008 and has been one of the strongest progressive voices in the caucus, especially in the Trump era. He has been particularly forceful in demanding answers from Attorney General Jeff Sessions, who has repeatedly changed his story about his knowledge of the Trump campaign's interactions with Russia.
Despite his work, Democrats have forcefully declared that Franken's alleged behavior, despite his apologies, disqualifies him from serving in the Senate. Earlier this week, Democrats also forced Rep. John Conyers of Michigan to resign after multiple allegations of sexual harassment.
Democrats' actions this week stand in stark contrast to Republicans' embrace of Trump, Moore, and other sexual predators, and it's a reminder that sexual misconduct should not be tolerated, regardless of party.