WASHINGTON – Facing a barrage of sexual harassment complaints and calls to step down from friends and foes alike, Sen. Al Franken took to the floor of the U.S. Senate Thursday to announce he would resign — a swift and historic fall for an unlikely Minnesota politician who had become one of the Democratic Party's most recognizable leaders.

Franken was quick to explain that he was stepping down not because he thought he had done something wrong, but because he had determined that Minnesotans deserved a senator who wasn't distracted by mounting allegations and a looming Senate Ethics Committee investigation.

"Minnesotans deserve a senator who can focus with all her energy on addressing the challenges they face every day," Franken said in a speech that lasted just over 10 minutes, as his wife and adult children looked down from the Senate gallery.

With Franken's imminent exit, DFL Gov. Mark Dayton now faces a high-stakes decision about whom to appoint as replacement. One option is a temporary fill-in who would not run in a November 2018 special election. Top Democrats, particularly in Washington, favor a replacement who wants to run, since occupying the seat for nearly a year would offer a strong head start.

Even as Franken bowed to his political reality, saying he could no longer be effective, he sought to clear his name.

"I know there's been a very different picture of me painted through the last few weeks, but I know who I really am," Franken said. Of the claims against him by more than half a dozen women, he said: "Some of the allegations aren't true. Others I remember differently."

Even as his political career crumbled, Franken sought to draw a distinction between himself and two Republicans also accused of mistreatment of women, President Donald Trump and Alabama Senate candidate Roy Moore.

"I of all people am aware that there is some irony in the fact that I am leaving while a man who has bragged on tape about his history of sexual assault sits in the Oval Office and a man who has repeatedly preyed on young girls campaigns for the Senate with the full support of his party," Franken said.

As two dozen fellow Democrats and a single Republican colleague looked on, Franken delivered a defiant political eulogy for his eight years in the Senate.

"I know in my heart that nothing I have done as a senator — nothing — has brought dishonor on this institution," Franken said. He later added: "What I want you to know is that even today, even on the worst day of my political life, I feel like it's all been worth it."

Reverberations back home

Franken's departure will shift Minnesota's political landscape for years. There will now be two U.S. Senate seats on the 2018 ballot, along with an open governor's race. Five of Minnesota's eight House seats could also be up for grabs, making for a political cycle that's likely to see tens of millions of dollars or more flowing into the state.

Dayton is expected to appoint a replacement soon. A Democratic source told the Star Tribune that Dayton is likely to appoint Lt. Gov. Tina Smith, and that she is not expected to run in the special election.

But other ambitious DFLers are likely to be interested or at least considered. In a statement issued after Franken's speech, Dayton said, "I expect to make and announce my decision in the next couple days."

Franken was not specific about when his resignation would take effect, saying only it would be "in the coming weeks." A spokesman later said no definite timeline had been set, and that Franken would continue to perform his duties until then.

Jennifer Duffy, senior editor at the Washington-based Cook Political Report, which provides nonpartisan political analysis, said Franken's delay in leaving is generous to his staff members, who will likely be out of work when he resigns. It also gives Dayton more time to settle on a replacement.

She said Dayton may want to appoint a "caretaker," like Smith, though Senate Democratic leaders would probably prefer a replacement who could immediately begin campaigning.

Dayton condemned Franken's behavior while still praising him as "very smart, very hardworking and very committed to Minnesota."

"I extend my deepest regrets to the women, who have had to endure their unwanted experiences with Senator Franken," Dayton said. "As a personal friend, my heart also goes out to Al and his family during this difficult time."

Allegations mounted

Franken's resignation capped three excruciating weeks of revelations and accusations from women who said they'd been groped, kissed or embarrassed during encounters with him over the years.

It started with a former USO entertainer who shared a photo of a grinning Franken, mugging for the camera with his hands hovering over her breasts as she slept during a flight back from Afghanistan in 2006. She also said that Franken kissed her without her consent while on the tour, and that he "mashed his lips against mine."

Within days, a Minnesota state fairgoer told CNN that her photo-op with the newly elected Franken ended with his hand clamped around her buttock.

When a seventh accuser came forward Wednesday, describing a kiss she said Franken tried to plant on her after a 2006 radio show, Franken's fellow Senate Democrats decided they'd had enough. Calls for his resignation peppered social media, starting with a half-dozen female Senate Democrats and snowballing until more than half the party's caucus had called for his ouster.

Even before his colleagues called for him to resign, Franken's stock in the Senate had plummeted — from a permanent fixture at party fundraisers and campaign rallies to a figure of public scorn, whose donations to other candidates were regifted to shelters for abused women.

Franken said Wednesday he still believed the Ethics Committee would have cleared him, and also said he feared his attempts to be respectful of the accounts of his accusers gave the "false impression" that he was admitting to the allegations.

"I think that was the right thing to do," he said. "I also think it gave some people the false impression that I was admitting to doing things that in fact I haven't done."

Franken had issued a series of apologies in response to each allegation, because, he said, "all women deserve to be heard and their experiences taken seriously." He did not repeat the apologies Thursday.

Some longtime supporters and allies continued to stand by him.

"Al has been an ardent advocate for women's rights and the people of Minnesota. I am grateful to have had the opportunity to work for him, and always will be," said Natalie Volin Lehr, who previously worked in Franken's office as political director and women's policy adviser.

"I am also a lawyer and firmly believe in due process — it is an absolute travesty that it has not been afforded to him."

Difficult time

A mob of reporters and photographers staked out a Capitol entrance for hours Thursday morning, waiting for Franken to appear. When he appeared with wife, Franni, at his side, they forced their way through the throng as several people in the crowd shouted for them to be let through.

The senators who gathered on the floor Thursday included several former allies who demanded Franken's resignation a day earlier. They listened in grim silence, a few wiping at their eyes. After his speech, they made themselves scarce.

"I'm not going to talk about Senator Franken but thank you very much," Sen. Claire McCaskill said as a reporter approached her. The Missouri Democrat was among the first to call for Franken's resignation.

Sen. Amy Klobuchar, Franken's fellow Minnesota Democrat, said she privately urged him to resign when they spoke Wednesday. The next day, she was first to arrive in the Senate chamber. She spoke to the long line of Franken staffers who sat watching at the back of the chamber.

"I didn't think that many of our colleagues would come, honestly, after calling for his resignation," Klobuchar said. "I thought it was good that there were a number of people there."

As for the speech itself, she said: "I know he didn't really apologize to the people, and that would have been nice. But I think the bigger deal for me was that he was able to talk with a lot of love about our state, and what he liked about his job and what he wanted to be his legacy."

That legacy looked like it would be very different a few weeks ago. After eight years in the Senate, Franken had emerged as a powerful voice for progressive causes and forceful critic of the Trump administration, getting national attention with aggressive questioning of Trump's Cabinet officers.

Franken's voice

As Franken stepped down, he went down swinging. He was giving up his Senate seat, he said, "but I am not giving up my voice."

He said he would "continue to stand up for the things I believe in as a citizen and as an activist."

Talking about the national debate shifting to focus on the mistreatment of women and consequences for their abusers, Franken said, "I was excited about the conversation and I hoped it would result in real change. Then the conversation turned to me."

The same forces that pushed Franken out of office — women speaking out publicly against men who use their power to hurt and harass others — have pushed countless newcomers into politics for the first time this year. That's good, Franken said, offering up his own painful fall as an object lesson.

"You too will experience setbacks and defeats and disappointments. There will be days when you will wonder whether it's worth it," he said. "For a decade now, every time I would get tired or discouraged or frustrated, I would think about the people I was doing this for and it would get me back up on my feet."

After his speech, Franken and Franni left the Capitol, hand in hand, chased by a horde of reporters.

Asked if he had anything to tell the people of Minnesota, Franken replied: "I'm coming home."