WASHINGTON – Sen. Al Franken's decision to quit the U.S. Senate leaves Minnesota suddenly without its most high-profile politician, a feisty Democratic brawler who leveraged being a household name into the pursuit of a range of progressive causes.

Franken's unlikely journey from "Saturday Night Live" personality to U.S. senator gave him the kind of national celebrity that eludes most politicians, even those prominent in Washington. And as he sought to show voters he was more than just a comedian, Franken embraced an ambitious policy agenda on issues large and small — championing internet deregulation one day, relentlessly interrogating members of President Trump's Cabinet the next, then reaping millions for Democratic candidates as one of his party's most prolific fundraisers.

"He was ahead of his time," said fellow Sen. Amy Klobuchar, D-Minn., citing Franken's work to prevent technology companies from mining and profiting off the personal information of their customers. "I think that work will last."

Unfortunately for Franken, his political career is now likely to be most remembered for its messy, abrupt end. His announcement Thursday that he would resign in the coming weeks, following sexual harassment allegations by more than half a dozen women, came in a floor speech that displayed most of the aspects of Franken's public persona — at times sentimental, at times acerbic, at times the proud progressive.

"Kids facing bullying. Seniors worried about the price of prescription drugs. Native Americans who have been overlooked for far too long. Working people who've taken it on the chin for a generation. Everyone in the middle class and everyone aspiring to join it," Franken said in his resignation speech, describing how he tried to "fight for the people who needed us."

For most of his time in the Senate, Democrats were in the minority. But Franken was able to leave his imprint, forming partnerships with Republicans on some issues while serving as a reliable voice from the left on others. As Democrats worked to pass the Affordable Care Act, Franken attached a requirement that insurers spend at least 80 percent of collected premiums on actual health services for patients. And he teamed with a Georgia Republican to establish a pilot program at the Department of Veterans Affairs to provide disabled veterans with service dogs.

Franken, 66, was born in New York City, but his family moved to Minnesota when he was a young child. He lived in St. Louis Park and graduated from the Blake School. After decades in which he was a "Saturday Night Live" writer and performer, a writer of bestselling political satire and a nationally syndicated radio host, Franken launched his political career in 2007 by announcing a run for the Senate seat once held by his political idol, Sen. Paul Wellstone.

Franken adopted some of Wellstone's own priorities, like the push to ensure that mental health services be a basic part of insurance policies, and he frequently invoked Wellstone in his resignation speech.

"Politics, Paul Wellstone told us, is about the improvement of people's lives," Franken said.

The 2008 Senate election against Republican Sen. Norm Coleman was intensely fought, and Franken had to answer for decades of written and performed material that often seemed to cross a line into what even many allies called sexist or mean-spirited. After the vote ended in a near-tie, Franken prevailed after two recounts and a lengthy lawsuit. He finally joined the Senate in July 2009, vowing to retire his image as a caustic comedian in favor of being hardworking policy wonk.

As a senator, Franken took on conflicts of interest at credit rating agencies in the Dodd-Frank bill that overhauled banking regulations in the wake of the financial crisis. In the Violence Against Women Reauthorization Act of 2013, Franken wrote provisions that meant survivors of sexual assault would no longer have to pay for their rape kits and banned the eviction of domestic violence victims from federal housing.

"If you had to pick a word for Al Franken as a senator, it's 'studious.' He really studies the issues hard, he's serious about them, and he's effective," Sen. Chuck Schumer of New York, the Senate's Democratic leader, told the New York Times in 2014. But Schumer was among the large group of Democratic colleagues who on Wednesday turned on Franken, demanding his resignation.

Franken also became known for taking on major communications companies. He tried to block the merger of Comcast-NBC Universal, and later Comcast's bid to acquire Time Warner Cable. He pushed Facebook to do more to protect users' privacy.

The senator became one of the most prominent voices on net neutrality, the concept that internet service providers should offer the same access to all content without blocking or favoring certain websites. Even as recently as this week, Franken tweeted about Federal Communications Chairman Ajit Pai moving ahead with a Dec. 14 vote "on a policy that would destroy net neutrality." He called for the vote to be delayed and said the internet as customers know it is at serious risk.

After Franken handily won his 2014 re-election, he started to get more comfortable showing his humorous side, appearing more frequently on nonpolitical talk shows. But he never forgot how he barely eked out a win during his first run for office, and used his star power to help Democrats across the country.

"You are looking at a senator who won by 312 votes," Franken told a crowd in Massachusetts in 2012 as he campaigned for Elizabeth Warren. "My charge to you is, 'Work your butts off.' "

Franken said he was devastated by Trump's election, but it presented an opportunity. He became a tough questioner of Trump administration appointees in Senate committees, and before long national media outlets and pundits were floating Franken as a possible Democratic presidential candidate in 2020 — a politician who already had a national profile, fundraising prowess and popularity in the party.

As allegations against Franken mounted in recent weeks, all that quickly unraveled. He acknowledged as much in his speech Thursday, professing innocence but admitting he'd lost his ability to be an effective senator because of the allegations.

Franken was often asked over the years whether being a senator was as much fun as being on SNL.

No, he's admitted, it's not. But being a senator, he said, was the best job he ever had.

Star Tribune reporter Jennifer Brooks contributed to this report.

Maya Rao • 202-662-7433