His chief rival, Vincent C. Gray, meanwhile, was dropping in at no fewer than three black churches, in the Mount Vernon, Shaw and Fort Lincoln neighborhoods.

The election wasn't lost or won in a weekend, but how the candidates spent that time says something about why Gray defeated a sitting mayor with a long list of accomplishments.

Four years ago, Fenty captured the mayoralty as an Obama-style, post-racial black politician, one whose candidacy was not defined by race but by talk of competence, government efficiency and "best practices." It was an approach that was embraced by a broad coalition of white and black voters alike.

As mayor, Fenty retained his overwhelming popularity among white voters, as a breakdown of last Tuesday's vote demonstrates. But he lost the support of vast numbers of black voters who derided him for ignoring their communities and slashing government jobs. Many of those jobs were held by African Americans, who since the advent of D.C. home rule have used city employment as a stepping stone to the middle class.

As Fenty's mayoralty unfolded, discontent among black voters spread across the city, from affluent enclaves bordering upper 16th Street NW to middle-income areas such as Deanwood, in Northeast, and blue-collar neighborhoods east of the Anacostia River.

A Washington Post analysis of Tuesday's primary shows the extent of that disaffection. Fenty won 53 of the city's majority-white census tracts but only 10 of those that are predominantly black. Gray, in contrast, captured 108 majority-black census tracts and just five that are majority-white.

Kelvin Carvana, 42, a black resident of Shepherd Park, in Northwest, who works in construction finance, said he was struck by the dearth of black appointees in the mayor's Cabinet. And he walked away from Fenty.

"In this area, you have the most educated, affluent collection of people of color in the entire country," Carvana said. "We're all articulate, we're all perceptive, and he didn't realize that that was his market. He thought he could just run roughshod and cater to whomever he wanted to cater to and leave people disenfranchised. He just thought we were going to sit there and take it."

Although blacks and whites recognize the importance of the public schools as a vehicle for educating their children, blacks also see the school system as a primary employer, providing jobs to thousands of teachers, school bus drivers, administrators and secretaries. When Chancellor Michelle A. Rhee laid off hundreds of teachers, many blacks saw something more than a simple purge of poorly performing educators. They saw an assault on economic opportunity.

"He fired those teachers, that did it for me," said Wilson Givens, a retired, black equipment operator who lives in Anacostia, in Southeast, and voted for Fenty in 2006. "Does he understand that a job is a family's livelihood? I didn't know anybody who was fired personally, but I can relate. I know how it feels, and I felt for those teachers and their families. That was it for me. Would never trust him again."

At its core, the divide between how whites and African Americans viewed the election was rooted not so much in black-white tensions as in the perception among black residents that Fenty had disengaged from their communities. Frustration mounted as the Fenty administration added dog parks and miles of bike lanes while unemployment in Ward 8, home to the city's poorest neighborhoods, reached 30 percent.

It hardly mattered that the city's most prominent cyclist - the mayor himself - was black. The symbolism of putting city resources into amenities that seemed aimed at the District's gentrifying neighborhoods spoke powerfully to many African Americans, as did the mayor's selection of his first city administrator, police chief, fire chief, attorney general and schools chancellor, not one of them black.

Michael Fauntroy, a public policy professor at George Mason University, said Fenty's defeat sent a "message" that he hopes is being noticed in the White House. "If you're winning coalition includes significant numbers of African American voters, you better not run away from them," Fauntroy said. "You don't have to do everything they want, but you can't run away from them. And while I'm not saying this is what Adrian did, that is the perception in much of the city."

Many black voters said they were attracted by Gray's evident commitment to the public schools and alienated by what they saw as Fenty's bashing of the system and the people who worked in it.

White voters often had a different attitude toward education reform, in part because they lacked the emotional ties to city schools common among the many black families that have lived in the District for generations.

Allison Tierney, 45, mother of three and a white resident of Tenleytown, in Northwest, said she voted for Fenty exactly because he was shaking up the school system. "Most of them, probably all of them, needed to be let go," she said of the fired teachers. "They were there too long, and they needed a change."

Fenty's diminished standing among black voters may be traceable in part to generational changes in black leadership.

The civil rights movement of the 1950s and '60s gave rise to a generation of black politicians that included the Rev. Jesse Jackson, five-term Detroit mayor Coleman Young and the District's own Marion Barry, a four-term mayor who now represents Ward 8 on the D.C. Council. They championed racial justice, and their appeal was rooted in racial identity and pride.

They were followed by a wave of black politicians who adopted an executive tone and emphasized competency rather than race. This group included former Detroit mayor Dennis Archer, Newark Mayor Cory Booker, and Fenty's predecessor, Anthony A. Williams.

Although many black Washingtonians dismissed Williams as aloof and disengaged, the criticism did not define him as it has Fenty. Williams took office after serving as the city's chief financial officer and often joked about having the charisma of an accountant. He also followed Barry at a moment when black and white voters seemed united in wanting a calming mayor, who would restore fiscal order to a city that had suffered the embarrassment of a federal takeover in the form of an emergency control board.

Fenty, by contrast, drew attention during his 2006 campaign by knocking on thousands of doors across the city. His message was not overtly racial, but he connected with many black voters by emphasizing his roots as a lifelong Washingtonian and son of a prominent small businessman - and by leaving no doubt that he was hungry for the job and would devote superhuman energy to it.

If his policy decisions as mayor provoked criticism, he also hurt himself by missing opportunities to connect with black residents through symbolic gestures: He failed to meet with civil rights leader Dorothy Height, and he raced in a triathlon instead of going to church on the Sunday before the primary election.

Eddie Glaude, a professor of religion and African American studies at Princeton University, said Fenty's defeat "suggests that the model of deracialization might not be sustainable" and presents an opportunity "for us to think about the direction of African American politics. What are we to make of this new class of post-racial black leaders? What challenges will they face, and who will follow in their wake?"

Glaude continued: "On the one hand, we could say Fenty engaged in bad politics, and on the other, we could say that some of the expectations of the African American community were unfair. He had to govern D.C. within constraints, and given his accomplishments, this outcome can seem dangerously punitive and may suggest that there is a desire to go back to a form of politics that I find troublesome, which is the kind of cronyism and patronage that defined the Marion Barry years. But I don't think that's what's going on."

Andra Gillespie, a professor of African American politics at Emory University, said even candidates who position themselves as post-racial must find ways to "be real and human. It's not about learning to speak a certain way or telling stories or playing go-go music. It's being sensitive to your community. If you know that older black voters expect church visits and for you to go to funerals and you don't do that, you should expect some criticism."

The breakdown of Tuesday's vote tells the story. Gray won more than 80 percent of the vote in wards 7 and 8, the most predominantly black wards, where turnout rose more than 20 percent from 2006. In predominantly white Ward 3, Fenty won nearly 80 percent of the vote.

In Ward 4, Fenty's home base, the mayor won by 9,000 votes in 2006. This time, he lost by 4,000 votes. In Precinct 62, the area along 16th Street NW known as the "Gold Coast," where affluent blacks have lived for decades, the mayor suffered a dramatic reversal from four years ago. Then, Fenty won 63 percent. This time, Gray won 63 percent.

"Fenty was elected by us, and Fenty forgot about us," said Audrey Dixon, 63, a black school bus driver who lives in Petworth, in Northwest. She understands that the mayor has built recreation centers and that her neighborhood has gained housing and restaurants in recent years. But she also knows that she struggles to get by.

"I'm sure people will say we're ungrateful," she said. "People say, 'Look at those playgrounds.' Well, I'm too old for playgrounds. I'm one paycheck from losing my home. I'm supposed to be retiring."