New Yorkers on Tuesday elected their first Democratic mayor since 1989, choosing Bill de Blasio -- who has vowed to usher in a new era of liberal policies -- to lead America's biggest city.

De Blasio beat his Republican challenger Joe Lhota by a wide margin, pulling 73 percent of the vote with 99 percent of the precincts reporting.

The New York City election was one of several mayoral elections in major American cities Tuesday, with Detroit, Boston and Atlanta, among others, also picking new leaders. 

Former write-in candidate Mike Duggan won Detroit’s non-partisan election, though he will have limited power as the debt-ridden city moves toward the largest municipal bankruptcy in U.S. history under a state overseer. In Boston, voters chose Martin Walsh over fellow Democrat John Connolly to replace longtime Mayor Thomas Menino, and Democratic Mayor Kasim Reed was re-elected in Atlanta.

The New York mayoral election is the beginning of the city's farewell to Mayor Michael Bloomberg, who has helped shape the nation's biggest city for 12 years.

However, while polls show that New Yorkers largely approve of Bloomberg's record, those same surveys show a hunger for a change in style and tone.

De Blasio, who as the city's elected public advocate acts as an official watchdog, had a commanding lead over Lhota, the one-time deputy mayor to Rudy Giuliani, in every poll taken since the September primary.

De Blasio has positioned himself as a clean break with the Bloomberg years, promoting a sweeping liberal agenda that includes a tax increase on top earners to pay for universal pre-kindergarten and improved police-community relations. He also has reached out to those who say they feel slighted by what they believe were 12 years of Bloomberg's Manhattan-centric policies.

De Blasio is the first Democrat elected mayor since Dinkins in 1989. even though registered Democrats outnumber their Republican counterparts 6 to 1.

During the Democratic primary he was also the loudest voice calling to reform the New York Police Department's controversial stop-and-frisk practice . He was a distant fourth for much of the summer in the crowded primary, only to surge past former front-runners including Council Speaker Christine Quinn and ex-Congressman Anthony Weiner. 

Weiner, who once led in the polls, slipped to fourth place following a July admission that the explicit online relationships that led to his resignation from Congress continued as recently as last year.

Lhota, 59, the former head of the Metropolitan Transportation Authority, had pledged to continue many of Bloomberg's policies and suggested de Blasio would handcuff the NYPD by reforming stop-and-frisk, the tactic that allows police to stop anyone deemed suspicious. Its supporters believe it has driven down crime while critics, including de Blasio, think it unfairly targets minorities.

In Detroit, Duggan, who was once thought to have little chance of surviving the primary, beat Wayne County sheriff Benny Napoleon by 55 percent to 45 percent. He becomes the city's first white mayor since the early 1970s.

The former health care executive and his challenger both oppose the Michigan takeover of city finances by gubernatorial appointee Kevin Orr, a position Duggan reiterated Tuesday.

"I'm going to try to shorten Kevyn Orr's stay," Duggan told The Associated Press.

In Boston, Walsh will replace the city’s longest serving mayor Thomas Menino, who announced earlier this year he would not seek another term after more than two decades in office.

The 46-year-old Walsh relied on support from labor organizations to help his get-out-the-vote drive.

Walsh was a union official before being elected to the Massachusetts House in 1997. Connolly made education his core issue and was hoping an "army of moms" that appeared with him at campaign events would help propel him to the mayorship. The 40-year-old father of three was the only candidate to enter the race before Menino announced he wouldn't run again. 

Menino did not take sides in the race to succeed him, and on Tuesday would not say for whom he had voted. He added that he had no regrets about his decision to retire. 

"I made the decision in March and it's done. I'm at peace of mind with myself," the mayor said after voting in his home neighborhood of Hyde Park.  

Menino said he would watch the election returns from his City Hall office and phone the winner to wish him luck. 

The White House said President Obama called De Blasio and Walsh Tuesday night to congratulate them on their election victories and vowed to work with them in the months ahead to expand economic opportunity for middle-class families in their communities.

As expected, Atlanta Mayor Kasim Reed sailed to his second four-year term by a wide margin, beating three lesser-known challengers. 

Reed, who previously served as a member of the Georgia General Assembly for 11 years as both a state senator and a state representative, is considered a rising star in the Democratic Party and was backed by President Obama, who said in an Oct. 29 statement Reed has “earned” a second term. 

The Associated Press contributed to this report