Bill de Blasio, who transformed himself from a little-known occupant of an obscure office into the fiery voice of New York’s disillusionment with a new gilded age, was elected the city’s 109th mayor on Tuesday.
His overwhelming victory, stretching from the working-class precincts of central Brooklyn to the suburban streets of northern Queens, amounted to a forceful rejection of the hard-nosed, business-minded style of governance that reigned at City Hall for the past two decades and a sharp leftward turn for the nation’s largest metropolis.
Mr. de Blasio, a Democrat who is the city’s public advocate, defeated his Republican opponent, Joseph J. Lhota, a former chairman of the Metropolitan Transportation Authority, by a wide margin.
Exit polls conducted by Edison Research suggested that the sweep of his victory cut across all of New York’s traditional divides. He won support from voters regardless of race, gender, age, education, religion or income, according to the exit poll.
Over disappointed boos, Mr. Lhota, 57, conceded the race from behind a wooden lectern at the Gansevoort Park Avenue hotel in Manhattan, saying, “I wish the outcome had been different.” But he struck a defiant tone, mocking Mr. de Blasio’s campaign slogan, “a tale of two cities,” by quipping that “despite what you might have heard, we are one city,” and adding, “I do hope the mayor-elect understands this, before it’s too late.”
The lopsided outcome represented the triumph of a populist message over a formidable résumé in a campaign that became a referendum on an entire era, starting with Mayor Rudolph W. Giuliani and ending with the incumbent mayor,Michael R. Bloomberg.
Throughout the race, Mr. de Blasio overshadowed his opponent by channeling New Yorkers’ rising frustrations with income inequality, aggressive policing tactics and lack of affordable housing, and by declaring that the ever-improving city need not leave so many behind.
To an unusual degree, he relied on his own biracial family to connect with an increasingly diverse electorate, electrifying voters with a television commercial featuring his charismatic teenage son, Dante, who has a towering Afro.
In interviews on Election Day, voters across the five boroughs said that his message had captured their deep-seated grievances and yearning for change.
Darrian Smith, a 48-year-old custodian at a public school in Brownsville, Brooklyn, said his vote for Mr. de Blasio was a plea to end the widespread police searches, known as thestop-and-frisk policy, that have repeatedly ensnared him and his African-American neighbors.
“When I look at Mr. de Blasio, I see a bright light at the end of the tunnel,” he said.
Jon Kopita, an educational consultant from Greenwich Village, called Mr. de Blasio the best hope for slowing the growth of luxury condominiums that crowd his Manhattan neighborhood.
“If it just becomes a rich person’s city, then I might as well just go live somewhere else,” he said. “It’s time to go in a different direction.”
The traditional Republican Party playbook that had propelled Mr. Giuliani and Mr. Bloomberg to victory in an overwhelmingly Democratic city — reaching across party lines to voters worried about crime, education and quality of life — felt outdated this campaign season. Even traditionally conservative-leaning neighborhoods fell to Mr. de Blasio.
He will become the first Democrat to lead New York in a generation, ending his party’s two-decade-long exile from City Hall.
“It’s huge,” said John H. Mollenkopf, director of the Center for Urban Research at the City University of New York, who added that Mr. de Blasio had shown that Democrats were again willing to entrust City Hall to one of their own.
“Liberalism,” Mr. Mollenkopf said, “is not dead in New York City.”
Mr. Lhota, a 57-year-old former deputy mayor in the Giuliani administration and onetime Wall Street banker, had entered the race with great fanfare and promise: as a moderate Republican, a battle-tested manager and an outsize personality, known for quoting verbatim from “The Godfather” and posting tipsy messages on Twitter.
But the first-time candidate proved listless on the stump, prone to monotone delivery. His attacks on Mr. de Blasio, as a “socialist” who would invite a return to crime-riddled streets, had a shrill quality. And despite his deep ties to the business world, he struggled to persuade donors to take a chance on him in the face of daunting poll numbers.
In the end, he raised just $3.4 million, a third of the amount collected by Mr. de Blasio.
“He just hit a brick wall,” said Phil Ragusa, the chairman of the Republican Party in Queens. “You have to be well funded. That is a reality. Joe was not.”
Mr. Lhota’s most ardent supporters conceded that he had failed to make a convincing case for himself. “He just wasn’t compelling enough,” said Regina Kessler, 58, who lives on the Upper East Side.
On Tuesday, Mr. Lhota put on a brave face. He ate his favorite breakfast of sausage, eggs and cheese on a bagel; his wife donned her good-luck red, white and blue scarf; and he told a radio host that he was busy writing a victory speech. But privately he had no illusions, acknowledging that he planned to conduct what he called a post-campaign “autopsy” to figure out what went wrong.
Like many New Yorkers, he was taken aback by Mr. de Blasio’s improbable rise. Raised a Boston Red Sox fan in Massachusetts, Mr. de Blasio embraced the cause of leftist Sandinistas in Nicaragua as a young man, married a woman who once identified as lesbian, and has never managed an organization larger than 300 people.
But Mr. de Blasio, 52, a longtime political operative who ran campaigns for Hillary Rodham Clinton and Charles B. Rangel, oversaw a highly disciplined political machine that committed remarkably few errors and took little for granted, in stark contrast with Mr. Lhota.
On Election Day, Mr. de Blasio had amassed around 10,000 volunteers at 40 locations to turn out voters; Mr. Lhota recruited about 500 workers at nine locations.
Exit polls showed that the coordinated outreach paid off, with Mr. de Blasio capturing the majority of votes in the Bronx, Brooklyn, Manhattan and Queens.
Largely overlooked on Tuesday was the man who has dominated the city for the past 12 years and whose legacy was a divisive theme of the campaign: Mayor Bloomberg.
The mayor quietly cast his vote inside an Upper East Side school, amid reminders that his time at the pinnacle of municipal power was drawing to a close. When Mr. Bloomberg, dressed in a crimson tie and a crisp winter coat, showed up, the poll worker had a question. What was his first name, again?
As he left, clutching a loaf of banana bread and a plastic cup of coffee, a little boy waved at his king-size S.U.V., and yelled.
“Bye, bye, mayor!”
