As the world’s financial structures buckle and sway, seemingly on the verge of collapse, Barney Frank lumbers into a threadbare AM-radio station in the old mill town of Brockton, Massachusetts. He is, as usual, a bit exasperated—and he seems close to sartorial entropy, his shirt half tucked, cuffs unfastened, and tie skewed at an unlikely angle.

These are harried times for Frank, the famously irascible chairman of the House Financial Services Committee. Since the financial system began tottering in the fall, Frank has joined Treasury Secretary Henry Paulson and Federal Reserve Chairman Ben Bernanke in an informal troika of crisis managers, pushing through hundreds of billions of dollars in bailout money as institution after institution, industry after industry, slides toward insolvency. (View an interactive feature showing how the federal government has intervened during times of economic crisis.)

The measures are unpopular even among many of Frank’s fellow congressional Democrats. But they are unfathomable in Brockton, a working-class burg where boxer Rocky Marciano remains a hometown hero 50 years after his last bout. Frank settles into a chair in the station’s studio. Adam Bond, a talk show host in a baseball cap, is finishing up with another guest, the ruddy-faced owner of a nearby dog track.

Frank is under the impression that he’s there to talk about local issues in the district he has represented for nearly three decades. But Bond immediately bores in on the financial crisis and Frank’s role in it.

“Is your position that in this fiasco you are without fault?” Bond asks. “Or that you’re no more at fault than anybody else?”

The congressman, his lips pursed and gray hair mussed, lurches forward in his seat. Bond is treading on his already frayed nerves. Much to Frank’s dismay, this is a question he is hearing everywhere. No Democrat in America is more closely associated with the bailout plan. For the 68-year-old Frank, the economic collapse offers a chance to build his legacy as a great lawmaker, remaking the nation’s financial system by enacting changes comparable, in Frank’s typically immodest estimation, to the greatest reforms of the New Deal.

“Our job next year,” he says, batting away Bond’s questions, “is to do what Franklin Roosevelt did in the 1930s.”

Bond is having none of it. He pulls out a list of campaign contributions showing that Frank has received more than $40,000 from the quasi-public mortgage giants Fannie Mae and Freddie Mac over a 20-year period. The amount is far smaller than the sums others accepted, but the implication is that Frank was as much an accomplice as a reformer.

Frank becomes irate, repeatedly pointing out that during the period Bond is highlighting, the Republicans were in control of Congress. “I was in the minority when these things were happening,” Frank says. “You’re asking me to account for them. I can’t account for other people’s mistakes!”

The interview ends, and Bond’s wife and producer, Victoria, escorts Frank out.

“Did you enjoy yourself?” she asks, as they ride down in a cramped elevator together.

Frank shoots her a glowering look. “No,” he replies curtly.

Outside, Victoria tries to apologize; her husband didn’t mean to offend, she says. Frank, unmoved, disappears into a late-model S.U.V.  The producer returns to the studio, her eyes full of tears.

With the nation’s economy in meltdown, the nexus of American capitalism has shifted to Washington. Congress, led by Frank’s committee, is now in the process of deciding the future regulatory structure of Wall Street, the pay of investment-banking executives, the fate of Detroit’s Big Three auto­makers, and how many homeowners will face foreclosure. Not since the New Deal has Washington assumed so much power over private industry so quickly.

In some ways, Frank—an inelegant, blasphemous career politician whose very job depends on the approval of voters like the Bonds and their listeners—personifies everything Wall Street fears about Congress’ motives and capabilities.

Frank is famous for his biting wit and volcanic temper, for ridiculing arguments that he finds stupid, and for administering tongue-lashings to the industry executives in both public and private settings. A former Harvard Ph.D. candidate (he later earned a J.D. from the school), his only business experience comes from pumping gas at his father’s truck stop as a youth in Bayonne, New Jersey. His proclamation of a new era of regulation—and bold dismissal of more-cautious voices—has heightened already stratospheric anxieties on Wall Street, leading some to question whether Frank—or indeed, Congress—has the proper temperament and experience to rewrite the rules of the complex world of finance.

“I am apprehensive,” said Stephen Friedman, the former Goldman Sachs chairman who heads the New York Federal Reserve, in response to a question about Frank’s efforts during a panel discussion with bankers. “It is a frightening thought to me that Congress, without immense preparation, would try to take on that job and try to do it in a period where there would be thoughts of retribution and punishment and populism.”

Friedman was speaking at the Council on Foreign Relations in New York, in a wood-paneled hall packed with shell-shocked investment bankers and corporate lawyers on a grim morning in late November. The day before, the government had announced its second bailout of Citigroup, following a fretful week in which the bank’s stock fell below $5 a share and the giant institution appeared to teeter on the brink of bankruptcy. Still, William Donaldson, the co-founder and former C.E.O. of Donaldson Lufkin & Jenrette and a former S.E.C. chairman, warned the panel that hasty congressional action to impose new rules is “one of the big dangers now.”

Friedman, like other Wall Street elders, has suggested postponing changes until both markets and emotions have stabilized and appointing a “blue ribbon” panel (classic Washington-speak for punting on a tough issue) to study possible strategies. Frank says such an idea is “nonsense.” He has no sympathy for the hedge fund managers and other financial wizards who invented what he calls “magical money machines.”

As Frank explains to me, “They became intoxicated by their own technology.” Listening to him detailing his plans at a mile-a-minute pace, predicting the return of Roosevelt-style government, and heralding the inexorable ascendancy of liberal politics, intoxication is a word that naturally comes to mind, and one can’t help but recall other eras of inflated ambition. In business, they’re called bubbles; in politics, they’re called revolutions. When asked about the possibility that emboldened Democrats could go too far, Frank dismisses the historical precedents with typical self-assurance.

“That’s overlearning from history,” he snaps. “Who are the unreasonable people who are going to overreach?”

Frank, regarded even by many foes as having one of the sharpest minds in Congress, has never felt it was his role to dream up overarching theories. Rather, he chooses from others’ ideas, guided by his principles. At present, those principles are clear: He believes that the government should use its muscle to regulate the financial system. He believes that executive compensation at public companies should be capped. He believes that income inequality lies at the root of many of the country’s economic troubles and thinks taxes should therefore be used to redistribute wealth to the poor. He believes that derivatives markets and hedge fund activity should be brought into the open and subjected to rules and that the United States should sacrifice some measure of economic sovereignty to international regulatory institutions.

All of these ideas would have been controversial—some politically unthinkable—even a few months ago. Now, says Peter Wallison, a financial-policy fellow at the conservative American Enterprise Institute and a former adviser to Ronald Reagan, “he might actually get them done, and that worries me tremendously.”

The hotheaded right regards Frank as an easily ridiculed foil. He walks like a penguin and speaks in a distinctively sibilant, rapid-fire patois, casually tossing off references to economist Joseph Schumpeter, philosopher Georg Hegel, and comedian Henny Youngman. “I think the fact that I’m gay is part of the subtext,” Frank says. He came out of the closet in 1987, the first congressman to willingly do so, and since then, his name has been synonymous in certain circles with the brand of free-spending, free-loving liberalism that conservatives love to run against. Now his role in the economic crisis has further elevated his profile, making him prime fodder for the cable-television screamers.

In a confrontation that gained him instant immortality on YouTube, Frank found himself cast as the villain in a shouting match with Bill O’Reilly over the mortgage crisis. The Fox News host insisted that Frank, through his career-long push to expand housing options for lower-income families, was responsible for enlarging the portfolios of Fannie Mae and Freddie Mac and ultimately culpable for the meltdown of the two institutions. That is the Republican line of attack on Frank, and it enrages him, because when the G.O.P. ran Congress, nothing was done to rein in the companies’ ballooning balance sheets. Frank was the one who pushed through an oversight bill after the Democrats took control in 2007.

The truth is, for a long time, both parties prized homeownership above all else, but Frank was more skeptical than most, wondering aloud in public settings how all those subprime mortgages were ever going to be paid off. This legislative history is tangled, though, not easily reduced to a sound bite. O’Reilly had already devoted a segment of a previous show to one of Frank’s former partners, Herb Moses, an economist who once worked for Fannie Mae. (The two men broke up in 1998.) Now O’Reilly bellowed that Frank, unlike S.E.C. Chairman Christopher Cox, didn’t have the guts to admit fault in the widening economic mess.

FRANK: No, this is why your stupidity gets in the way of rational discussion. The fact is, it was 1994 that we passed a bill to tell the Fed to stop the subprime lending. We tried to get them to do it. The first time we were in power again, in 2007, we passed the bill to regulate Fannie Mae and Freddie Mac.
O'REILLY: Look, Congressman, you tried to put a happy face on this.
FRANK: I’m not putting a happy face on anything.
O'REILLY: At least Cox is man enough to say he screwed up. You’re not.
FRANK: Hey, Bill. This manliness stuff is very unbecoming from you.
O'REILLY: Cox is man enough to say he screwed up. You’re not.
FRANK: You think toughness is yelling and ranting and trying to bully. It’s not going to work with me.

Frank, who once said that in politics, “imitation isn’t the sincerest form of flattery—denunciation is,” later turned the showdown into a campaign ad with the opening line “The right wing is losing control.”

But the criticism keeps coming. After his tense radio interview—which contained echoes of the O’Reilly episode—Frank, sitting in the front passenger seat of his S.U.V., continues to stew: He was sure that Adam Bond, the radio host, had been fed his information by conservative blogs. He was certain that Grover Norquist, a tax-hating, fiery-mouthed G.O.P. operative, was behind it. Norquist, he says, is the one telling Republicans to bring up his name in connection with Fannie Mae whenever possible.

Later, I call Norquist. He reciprocates Frank’s hostility. “He’s our No. 1 enemy,” declares Norquist, whose antitax lobbying group, Americans for Tax Reform, has long been a thorn in the side of Democrats. “He’s responsible for something that dwarfs Enron.”

Norquist laughs off suggestions of other motives. “This is a guy who’s never made a mistake in his life, and everything is because we’re homophobic,” he says.

Frank’s relations with others in Washington, both on the left and right, are more complicated. Amid the cascading series of financial failures in the fall, Frank, oddly enough, found his most productive working relationship to be with Treasury Secretary Paulson, a wealthy former Goldman Sachs chairman. For his part, Paulson became far more comfortable dealing with Frank than with his fellow Republicans in Congress.

The two men consulted on a daily basis during critical periods of the crisis, sometimes face-to-face, more often in impromptu phone calls. They communicate very differently: Paulson sometimes descends into halting jargon, while Frank can cram three sentence fragments into one breath. But a trusting relationship was formed. When Paulson said he needed $700 billion, it was Frank who expended the mighty effort to persuade resistant House Democrats. When President Bush called an emergency White House meeting, to be attended by both presidential candidates, it was Frank who peppered the president’s aides with detailed queries about the proposed bailout plan.

“When I talk to him about the markets, I know he immediately gets it,” Paulson told me at the height of the crisis. “And he has been consistently right in the advice he has given me about politics.”

The two reached a level of comfort with each other that allowed them to dispense with formalities. Just after the House passed the bailout package, Frank’s cell phone rang during a briefing to the press. “I’ll call him back,” he barked and snapped it shut.

“Was that the president?” a reporter joked.

“No,” Frank replied, in all seriousness. “It was the secretary of the Treasury.”

But as the crisis continued to unfold and Paulson pushed to broaden government aid to more industries and companies, the relationship became strained. Frank saw Paulson sinking money into an ever-widening pool of private interests—corporate lenders, credit-card companies, the hemorrhaging insurance firm A.I.G.—while resisting even a relatively modest effort to provide relief to indebted homeowners or failing automakers, two constituencies important to congressional Democrats. At the same time, the press was full of reports that big banks were simply holding on to their shares of the $700 billion or planning to use the money to acquire smaller banks.

After John Thain, the C.E.O. of Merrill Lynch, publicly referred to the bailout money as a “cushion”—implying that the firm was going to sit on it rather than lend it—an incensed Frank, who called it “infuriating,” phoned Paulson to complain.

“He said, ‘I agree with you. I’ve privately criticized him,’ ” Frank recalls. “I said, ‘Well, you’ve got to do it publicly’—which he has not.” (A Merrill Lynch spokesman declined to comment. The firm won’t receive federal aid until it completes its merger with Bank of America.)

Frank is already close with Paulson’s successor, Tim Geithner, whom Frank has known since the Clinton administration, when Geithner was at Treasury and the two collaborated on issues related to the World Bank. When the Fed sponsored an event to honor its gay employees, Frank and Geithner both attended. Frank keeps a picture on his desk of the two of them at the ceremony.

But Frank’s relationship with the new president is still largely uncharted. He supported Hillary Clinton in the primaries and was initially dubious about what he called Obama’s “very labored authenticity.” Since then, he says he has come to appreciate the new president’s calm and thoughtfulness. During the transition period, however, Frank expressed concern to me that Obama’s deliberate style was doing harm, and he went so far as to invoke the precedent of Herbert Hoover’s disastrous handover to Roosevelt. “I am a little troubled,” he said in early December. “Damage is being done by the fact that nothing is being decided.”

Meanwhile, Frank was also encountering disenchantment on his left, and by mid-December, signs of internal party dissent had burst into the open. During a contentious hearing that month on the subject of oversight of the bailout, Democratic members of Frank’s committee complained that they’d been “bamboozled,” asked why Frank had not yet called any bank C.E.O.’s before the committee to defend their management of the federal funding, and wondered aloud whether “Goldman Sachs is running this country.” Maxine Waters, a liberal Democratic congresswoman from California, took on the chairman directly. “I appreciate everything that you have done, but I’m not going to even cooperate with you anymore,” she said, staring down Frank. “You’ve been too kind, you’ve been too good, and you have allowed them to walk all over us.”

As she yielded the floor, Waters laughed nervously and braced herself for the response. “Please do not use your microphone,” she implored him.

Frank glared at her. “The gentlewoman,” he said, “does not have to worry about much further communication between us.”

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.”

Frank’s congressional district runs from Boston’s wealthy western suburbs down to the blue-collar fishing communities around Buzzards Bay and is shaped like a teardrop. As we barrel down Route 24, the highway that runs the length of his constituency, the congressman unfurls a newspaper. He doesn’t use a BlackBerry to get his news instantaneously; he didn’t start carrying a cell phone until 2004, when his staff and congressional colleagues demanded it. His driver, an armed plainclothes policeman who says his chief first selected him to drive for Frank because he is also gay, is using an audible G.P.S. system. Frank, who can’t stand the disruptions, turns it off.

The news in the paper, of bankruptcies and layoffs, is dismal. Critics of the bailout Frank worked so hard to pass say that it is foundering. Frank, like the rest of Congress, is in an untenable spot: catching blame for not spotting problems earlier and being accused of handing the responsible parties free money to clean up the mess. Frank is upset with Paulson because the Treasury secretary stubbornly refused to commit to the F.D.I.C.’s plan to spend $24 billion to help homeowners avoid foreclosure. Frank is equally impatient with some of his Democratic colleagues, who see any criticism of low-income mortgage holders as blaming the poor. “It turns out,” he says mordantly, “that nothing cures a lot of crap being put into the system.”
     
“Harm avoided,” Frank once told Federal Reserve chairman Ben Bernanke, “is rarely something on which you can run for reelection.” Frank believes that voters—and history—will judge the policy­makers in this crisis not by the problems they have for the moment solved but by the permanent reforms they leave behind. This is why Frank’s mind is already jumping ahead toward the day when it will be time to rebuild from the rubble.

For the first time in his congressional career, he sees Democrats working with an overwhelming electoral mandate. Despite his occasional criticism of Obama, Frank is heartened by the president’s personnel decisions. Obama’s chief of staff, Rahm Emanuel, is a former House colleague, and Geithner, of course, will have substantial say over the details of any regulatory changes, as will Obama’s other top economic advisers, Larry Summers and Paul Volcker.

Frank promises that the effort will be collaborative, but he has never been one to take marching orders.

“He’s not patient,” says Michael Paese, a former aide to Frank’s committee who is now an executive vice president of the Securities Industry and Financial Markets Association. “He’s 68 years old. He’s at the apogee of his life as a policymaker. He’s waited his whole life for this, and he’s not going to wait anymore. Forget it—that’s just not him.”

Frank intends to begin drafting legislation early this year. He says his first priority is broadening the regulatory authority the Fed already holds over major banks to encompass the entirety of the financial system, a change Geithner has also advocated.

“We’ve got to have a systemic risk regulator restraining people from doing things they shouldn’t do,” Frank says. He praises Bernanke—who he says has come to embrace a more aggressive role—in contrast with his immediate predecessor, Alan Greenspan. “I never joined in the veneration thing,” Frank says, adding that he believes the housing meltdown could have been averted had the former Fed chairman used his authority to curb the subprime-mortgage market. Greenspan recently admitted as much in congressional testimony, a mea culpa that Frank says was “comparable to McNamara’s on Vietnam.”

As a precedent for the scope of his envisioned regulatory expansion, Frank reaches back not just to the New Deal but to the era of Theodore Roosevelt and Woodrow Wilson, when the Federal Reserve System was established. “For Roosevelt and Wilson, it was the trusts, the large industrial enterprises, and for F.D.R., it was the stock market,” Frank says. “For us, it’s securitization.”

Frank expresses varying degrees of enthusiasm for some of the specific proposals currently floating around Washington, such as consolidating the alphabetical mishmash of agencies that regulate overlapping segments of the financial sector and removing derivatives—which evolved from grain futures—from the purview of the obscure Commodity Futures Trading Commission. Frank would like to put derivatives under the S.E.C., but doing so would probably spark a political fight with farming interests. As for the even thornier issue of Fannie Mae and Freddie Mac, Frank thinks they will ultimately be broken up into smaller companies with distinct purposes.

What is most important, Frank says, is that the new system be designed to promote better risk management. In the late 1990s, when a bipartisan coalition repealed parts of the Glass-Steagall Act, the Depression-era law that erected walls between depository banks and securities firms, Frank voted against it. Today, he feels as if his stance has been validated. Nonetheless, he recognizes that re-­creating the old barriers would be impossible.

He believes existing structures should be revamped to regulate activities rather than institutions, so that an insurance company that acts like a hedge fund or a hedge fund that acts like an investment bank would be governed by uniform rules administered by expert staff at the Fed. Of course, this will most likely run into opposition, particularly from some sectors of the insurance industry, which is regulated at the state level—an obstinate vestige of the 19th century—and hedge funds, which have traditionally resisted the slightest government oversight. That doesn’t deter Frank.

“No one will listen to them,” he says. “They have no power to resist.”