Al Franken's transformation from spicy comic to wonkish senator has been nothing short of breathtaking. Five years ago, the risk of encountering Franken was that he'd tell a funny story of the sort that would make your mother blush. Now the risk is that he'd make your eyes glaze over with the inside dope on Washington legislation. Franken has become, with no irony intended, a serious man.

"Is it as much fun being a senator as it was working on 'Saturday Night Live,' " he asks, reciting a question he often gets. "The answer is no." But he goes on to say that people's careers often take new turns. "This is the best job I've ever had," he says, "because its purpose is to improve other people's lives, and when that happens everything else is worth it."

"Everything else" is the endless partisan bickering and systematic dysfunction that have led many ordinary people to give up on government and some scholars to conclude that the Constitution no longer works. But Franken, a Democrat, who's rated among the half-dozen most liberal senators, insists that there's another Washington hiding in the nooks and crannies, one that's fully functional and brimming with bipartisan cooperation, even bipartisan friendship. "That's really what the job is about," he says.

Take, for example, the new restrictions on large-scale pharmaceutical compounding that Franken and Republican Pat Roberts of Kansas pushed through the Senate last year. Federal investigators had traced contaminated drugs that caused 750 cases of fungal meningitis and 64 deaths to a careless drug compounding operation in Massachusetts. Its tainted drugs were shipped to 18 states. At a tearful meeting last month in Franken's St. Paul office, two Minnesota survivors dropped by to thank Franken and to describe the painful illness that continues to threaten their lives. It was a heartbreaking scene. And it showed an emotional side of Franken that most voters haven't imagined.

But it also prompts a question as Franken braces for a re-election challenge this year: Who is this new Al Franken? His opponents tend to see him wearing a kind of disguise, beneath which lurks the same old prankster who wrote books like "Rush Limbaugh is a Big Fat Idiot" and "Lies and the Lying Liars Who Tell Them," wickedly funny essays with a streak of mean running through them. In short, they doubt the genuineness of the new Franken.

Friends, on the other hand, see common threads running through Franken's career, from comic to satirist to senator — namely, his intense interest in public affairs, his appetite for detail, and his strong sense of populist outrage, now tempered by age and position. For them, Franken has emerged as a mature version of his former self, or, in political terms, a buttoned-down version of Paul Wellstone, without the fizz.

Franken, himself, traces his political awareness to his father, who grew up a Jacob Javits Republican in New York and eventually moved his young family west, first to Albert Lea, then to the Twin Cities suburbs. Father and son would pull out the TV trays at dinnertime and watch the news together, most memorably the civil-rights drama of the early 1960s, and most vividly the scenes of white police officers attacking and beating black demonstrators. "No Jew can be for that," Franken recalls his dad telling him.

In 1964, when Republican presidential nominee Barry Goldwater failed to support the Civil Rights Act, Joe Franken switched parties. And his son began sipping St. Louis Park's extraordinary brew of politics and art, a mixture that would produce journalist Tom Friedman, satirist Tom Davis, filmmakers Joel and Ethan Coen, and musicians Sharon Isbin and Peter Himmelman, among others. The Blake School, Harvard University and Dudley Riggs' Brave New Workshop sharpened Franken's sense of irreverence and launched him toward a brand of politically edged comedy, eventually as a writer and occasional performer on "SNL" and as a talk-radio host who tried to challenge the conservatives' domination of the air waves.

But Franken's experience as a public figure did not prepare him for elective office. Early in his Senate campaign, he struggled to find the proper persona between comic and serious candidate. Speaking from the bimah (pulpit) at Temple Israel in Minneapolis, Franken told a graphic Buddy Hackett joke about male genitals. The response was shock and embarrassment. It may have been a moment of clarity for Franken: What works on the Borscht Belt or in Las Vegas is way, way out of bounds for a politician in the American heartland, especially in a sacred setting.

Later, during the momentous recount that followed the 2008 election, Hillary Rodham Clinton's chief of staff in the Senate, Tamera Luzzatto, hammered home a similar point. Don't take advantage of your celebrity, she told him. Avoid the national spotlight. Keep your head down. Work hard. Take care of constituents. Build a loyal staff. Earn the respect of your colleagues in both parties.

Not the Ted Cruz of the left

It's advice that Franken has followed almost too faithfully. "No one ever thought that Al Franken would be boring, but he's taught himself a whole new skill set," said University of Minnesota political scientist Larry Jacobs. "There's nothing in his past to suggest that he could be this disciplined and this effective. He has greatly exceeded expectations."

"He could have been the Ted Cruz of the left, but that has clearly not happened," said Carleton College's Steven Schier. "Turns out that the court jester was really an accountant."

Actually, Franken has employed some of his satirist skills in the Senate, namely his talent for scanning the news and selecting his targets — not for comedy sketches but for legislation. "I don't know of any first-term senator who has had such a broad sweep of accomplishments," said Norman Ornstein, a resident scholar at the American Enterprise Institute and one of the nation's foremost experts on Congress. (Ornstein, by the way, grew up in St. Louis Park, a few blocks from Franken, and considers him a personal friend.)

Perhaps the best example of Franken's sharp eye was noticing that Dodd-Frank, the law aimed at a preventing another 2008-type financial meltdown, had failed to discourage what Franken saw as a too-cozy relationship between the credit rating agencies and the Wall Street investment banks. Franken's clear impression was that the agencies gave AAA ratings to "junk" in exchange for continued business from the banks. "That was the cause of all this in the first place," he said. "This is a conflict of interest, clear as day."

While he's still working to amend that law — "I'm on it like a dog with a bone" — many of his other initiatives have been passed, nearly all of them with the help of Republican partners. Among Franken's main interests: privacy, technology, workforce development, veterans, health care, renewable energy and agriculture. Perhaps the best way to summarize his legislative work is to ask some of the questions he asked over the last five years:

Should insurance companies under Obamacare be required to spend 80 percent of premiums on actual care rather than on administrative expenses? Should the developers of smartphones and mobile apps be required to get customers' consent before tracking their locations? Should the federal government decline to do business with companies that require employees to give up the right to sue for sexual harassment or rape at work?

Should partnerships between private-sector employers and community/technical colleges be strengthened? Should veterans have better health care options in rural areas? Might service dogs help wounded veterans adjust to civilian life? Should diabetes prevention be a higher priority in health care? Should landlords be prohibited from evicting women from federally supported housing because they were beat up or sexually assaulted? Should spy agencies be required to release more details about their surveillance programs?

He believes that the answer to each of those questions is yes. Franken owes much of his success so far to his ability to forge alliances, even friendships, with Republican senators. A sense of humor on both sides can break down a lot of barriers, he said. "They figured out pretty quickly that I laugh a lot."

At the same time, he has emerged as perhaps the Senate's toughest critic of corporate power, especially in the wake of the Supreme Court's 2010 Citizens United decision, allowing unlimited corporate contributions to politicians. "They gave corporations a blank check to utterly destroy our political system," he told his colleagues in 2012.

Tough election ahead

Until President Obama's popularity began to unravel last fall, Franken was considered a heavy favorite for re-election this year. With high approval ratings (51 percent) and an impressive talent for fundraising, he's still favored to win. But Obama's slide has improved Republican chances for retaking the Senate next fall. And, in Minnesota, the corporate community has produced a candidate — financial executive Mike McFadden, a political novice — who may have enough money to overcome Tea Party opposition and emerge as Franken's November opponent.

A well-funded moderate with potential appeal to independent and suburban voters probably offers the GOP its best hope. Remember, Franken won a three-way race with less than 42 percent of the vote in 2008 — and by a microscopic margin (312 votes). He benefited from a heavy DFL turnout for Obama, a turnout he can't count on next fall. And his appeal to outstate voters was limited then and is probably still in doubt. Then there's his enthusiastic support for the Affordable Care Act, which stumbled badly out of the blocks. "His fingerprints are all over it," said Jacobs. "He can't run away from that one."

Franken acknowledges the challenge and says the best he can do is let the political chips fall and hope that voters see him as a surprisingly pragmatic problem-solver. In the end, low expectations may be his best friend. "It's great when people come up to me and say, 'I didn't vote for you but you're doing better than I expected."

Steve Berg is a Minneapolis writer and consultant. He covered Congress and national politics for the Star Tribune from 1981 to 1993.