Frank grew up in an era when Roose­velt’s expansive government was taken for granted, and he has spent much of his adult life fighting rearguard actions against Republican efforts to dismantle it. Coming from a striving working-class family, he developed an interest in politics as a teenager but felt he’d probably never be able to run for office because of his sexual orientation and religion. (He’s Jewish.) Instead, he joined civil rights marches in Mississippi and studied political science at Harvard, both as an undergraduate and a doctoral candidate. Even during this time, the ’60s, Frank never had sympathy for campus extremists. When a mob of protesters confronted Defense Secretary Robert McNamara, preventing him from giving a scheduled speech at Harvard, Frank was the one who rescued him from the confrontation, sneaking him out through the campus steam tunnels.

Frank took a break from his graduate studies in 1967 to plunge into the real-world politics of a Boston mayoral campaign, albeit in a behind-the-scenes role. Working for the young reformist candidate Kevin White, Frank made himself so indispensable that White, once elected, named him chief of staff. The inexperienced academic was soon thrown into a managerial role during one of the most tumultuous periods in Boston’s history, when racial tensions were exploding. “If you had described to me in January 1968, when I took over, what I was going to look at, I would have said, ‘Oh jeez, I can’t handle it,’ ” Frank says. “But the thing is, you do it. You don’t stop to think about it. And I learned that I was good at it.”

Frank reflected on his career during a campaign stop just before Election Day. Standing in a balloon-bedecked music room of a Catholic school in Newton, Massachusetts, Frank rocked gently on his heels, his hands clasped behind his back. Harsh as he can sometimes be with adults, his interaction with children is warm, without condescension; he even allows himself to become introspective. His bushy eyebrows danced as he responded to the precocious questioning of a group of fifth- and sixth-graders about how he decided to become a politician.

“Originally, I wanted to be a professor,” Frank said. “But then I went to work for the mayor, and I got a chance to test myself. And you know, you have to know what your strengths and weaknesses are. Some people like to take one project and work on it for a long time. That’s called having great powers of concentration. I’m different. I like to work on a lot of different things, and in politics I get to do that. So that’s what I realized. Unkind people would say that I have a short attention span. Not quite A.D.D. But if I work for too long on one thing, I get bored.”

For a public figure, Frank seems uncommonly honest about his shortcomings. He says his strength is quick comprehension. “But as you are expected to spend more and more time on fewer and fewer subjects, my comparative advantage diminishes,” he says. Being an academic required extended attention, but the whipsaw nature of politics played to his strengths. After leaving the Boston mayor’s office to make a halfhearted attempt to complete his Harvard doctorate, Frank quit academia for good to take a seat in the Massachusetts state legislature and earned a Harvard law degree on the side in 1977. He was elected to Congress in 1980 and has never faced much of an electoral challenge since.

When Frank first publicly admitted he was gay, he worried aloud, “All I’m going to be now is a gay-rights crusader.” Though his career was almost derailed a couple of years later by a highly publicized sex scandal involving his male housekeeper, a part-time prostitute, Americans have, over the years, surprised him. He often says that he has consistently failed to predict the pace of changing attitudes, and through many years of incremental change, he has become well-known among his colleagues for other qualities: his quick grasp of complexities, his decisiveness, and—surprising to anyone familiar with him only via caricatures—his ideological flexibility.

“I always felt that the emotional left did more harm than good to our causes,” Frank tells me. “Being gay has obviously been a part of it. I’ve always perceived myself as being different. And I didn’t have any option about challenging what other people did, because a very large part of me was very different from everybody else. And that may be part of the bond with me and Paulson. We are both impatient with people who claim to be our allies, who act out emotionally and don’t think and don’t accept restraints and try to reject reality.”

Within a few years after the sex scandal (which resulted in a formal House reprimand), Frank reassumed an influential position within his party. He published a book-length essay entitled “Speaking Frankly,” which he dedicated to his then partner, Herb Moses, whom he credited for being a stabilizing influence in his life. The essay argued that Democrats would keep on losing elections unless they demonstrated that they were “patriotic supporters of the free-enterprise system who think that hard work should be rewarded and violent criminals severely punished.”

Frank, who started out wanting to help the poor, ended up lording it over the rich. When he entered Congress, he sought an assignment to the Financial Services Committee, which deals with subsidized and public housing, a career-long interest for Frank. After the Democrats swept the 2006 midterm elections and he became chairman of the committee, he announced that addressing income inequality would be his foremost goal and said he planned to curb his renowned tongue. “I’ll have to be a little boring,” he told the Boston Globe.

That’s one political promise he has failed to keep. The near collapse of the financial markets and the almost unprecedented scale of government intervention to save them have created a void in leadership that Frank has barged into with characteristic bravado. Throughout the past few months, as it became clear that Congress would be called upon to create new regulatory structures, Frank has been brainstorming in both public hearings and private discussions. He has little formal training; though he took many economics courses as a Harvard undergrad 40 years ago, he didn’t major in the subject because he couldn’t do advanced math.

But his position as committee chair has allowed him to call on preeminent economists like Princeton’s Alan Blinder and Columbia’s Joseph Stiglitz, as well as heavyweights of the financial sector. “He was as knowledgeable about these issues as anyone could imagine,” said Rodgin Cohen, one of the nation’s most respected corporate lawyers specializing in finance, after meeting with Frank privately. “I was frankly astounded.”

Stiglitz, a Nobel laureate, has encountered Frank at prestigious gatherings like the recent World Economic Forum in Davos, Switzerland, and a conference hosted by the Tobin Project, an alliance of academics that’s named for Nobel-winning economist James Tobin. Few members of Congress venture to such events, which are far removed from the parochial concerns of their constituents. At the Tobin conference, though, Frank was “in his milieu,” Stiglitz recalls, and was treated like a star. “It wasn’t the ordinary politician giving a set of platitudes,” the economist says. “It was somebody trying to grapple with the problems in all their complexity.”