In the tortured political landscape of the District, Kwame R. Brown promised to be something different. In a city riven by race, class and the ever-looming threat of congressional intervention, Brown presented himself as a young African American who was equally comfortable in living rooms in Anacostia and Chevy Chase, a politician with street cred and boardroom savvy.

This was a different era from the days when a young Marion Barry could win elections alternating between a dashiki in Southeast and a three-piece suit in upper Northwest. The new Washington, Brown told audiences during his first run for the D.C. Council in 2004, needed someone who would act, look and speak the same way in all sections of the District.

In three elections, Brown — who resigned from office Wednesday night after federal prosecutors charged him with bank fraud — managed to bridge the chasms between rich and poor, black and white. His story of pulling himself up from a troubled youth, along with his pedigree as the son of one of the city’s most accomplished political operators, bolstered his image as someone who could empathize with those at the bottom even as he shared the values of the city’s burgeoning affluent class.

But on the council, Brown, 41, was dogged from start to finish by colleagues whose attitude toward him ranged from dismissive to derisive. Brown, they eagerly and regularly told reporters in not-for-attribution conversations, was a lightweight, not up to the job, in over his head. Whatever voters were buying wasn’t going over with the people who had to work with Brown.

But when the hammer came down on the council chairman, it was not for any misdeeds in office. The allegations were not even connected to his political nadir, the scandal last year after Brown asked city officials to get him a “fully loaded” $1,900-a-month Lincoln Navigator equipped with a DVD entertainment system, power moon roof and polished aluminum wheels.

The immediate cause of Brown’s downfall was his personal finances, which he admitted years ago were a shambles. “I am a bean counter,” candidate Brown told affluent voters in Ward 3. But at home, he was a mess: Three credit card companies sued him, alleging nonpayment of bills. His debt neared $1 million. And, federal prosecutors allege, he falsified records to obtain a home-equity loan and buy a $50,000 boat.

“To accuse him of exaggerating his income to get a loan is a personal foible,” said Tom Lindenfeld, a longtime D.C. political consultant and supporter of Brown’s. “It’s not lying and cheating to get elected. It’s not stealing $350,000 from the city. It’s a guy who got in over his head.”

There’s that phrase again. “Over his head.” A fellow council member used it about Brown just a few weeks ago: “Kwame is in way over his head,” said the veteran politician, who spoke on the condition of anonymity because he was slamming a colleague. “He cannot lead the council because he doesn’t have a nuanced knowledge of the budget or the government. We are paralyzed because the leader cannot lead and the leader is under a cloud.”

If Brown sometimes seemed oblivious to how he was perceived — he named his boat “Bullet Proof” and posted a sign in the cabin saying “If you have to ask, you can’t afford it” — his defenders say he thrived on being underestimated.

Voters saw in Brown a man willing to take political risks. White voters were impressed that he would adopt positions unpopular in parts of black Washington, including support of same-sex marriage and a ban on smoking in bars and restaurants.

Black voters heard Brown as an authentic voice for a Washington that seemed to be slipping away as African Americans become a minority where they were once two-thirds of the population. Last week, at the memorial service for go-go singer Chuck Brown, Kwame Brown zinged the city’s mostly white newcomers, reviving Barry’s 1994 slap at whites appalled by his return to the mayoralty after his prison term on drug charges: “For all of the people who just moved to Washington, D.C., and have a problem with go-go music,” the chairman said, “get over it.”

Brown’s cocky side reminded observers of his father, Marshall Brown, a political consultant who has worked on campaigns in the District for four decades. Although Kwame Brown grew up primarily with his mother in Prince William County, he was sent to live with his father while he attended Wilson High School during what he has called a troubled period.

More than a decade ago, the father predicted that his son would one day be mayor. Marshall Brown said the path to victory would combine a grass-roots campaign with a persona that let black voters know Kwame was “one of us, at the same time as he showed whites there was nothing scary about Kwame Brown.”

In 2004, in his first campaign, a scrappy Brown defeated well-funded incumbent Harold Brazil with the kind of door-to-door effort that brought former mayor Adrian M. Fenty (D) success. Brown won despite Brazil’s efforts to paint his challenger as someone who had failed to vote regularly and lied about his college credentials. (Brown ended up editing a flier that stated he had graduated from Dartmouth College’s business school when he had actually attended only a short program for minority executives.)

In that campaign, Brazil depicted Brown as a throwback, through his father, to the Barry era, a time of dysfunction, cronyism and profligate spending. But Kwame Brown called himself a reformer, aligning with Fenty, then a council member.

But the two had a falling-out, and by decade’s end, Brown had joined with Gray to portray Fenty as an out-of-touch mayor who cared only about the affluent, appealing to black voters to see Fenty as a mayor too devoted to the pet projects of affluent whites — dog parks, bike lanes, the smoking ban. But that shift in Brown’s message, along with his demands for a fancy SUV, caused some supporters to wonder: Was Brown simply out for himself?

Some council members barely bothered to consult with the chairman on initiatives. “Kwame does his own thing, which is all about Kwame,” one council member said. “He’s really not very interested in most of what we do.”

On his boat, Brown kept a copy of a book by Nicky Barnes, a New York drug dealer. The title: “Mr. Untouchable.”