NEW YORK — Billionaire Michael Bloomberg won a third term as New York mayor Tuesday in a closer-than-expected race against a Democratic challenger who stoked voter resentment over the way Bloomberg changed term-limits law so he could stay in office.
With 99 percent of precincts reporting, Bloomberg, the richest man in New York and founder of the financial information company Bloomberg LP, defeated William Thompson Jr. 51 percent to 46 percent.
In the days leading up to the election, polls showed Bloomberg with as much as an 18-point lead, an edge so big that critics accused the mayor of overkill in his strategy of bombarding the city with campaign ads.
His margin of victory was far smaller than the nearly 20-point blowout he pulled off in 2005.
When all the bills are paid, Bloomberg will probably have spent more than $100 million on his campaign, the most expensive self-financed campaign in U.S. history. Thompson, the city’s comptroller, relied on donations and matching funds for his mayoral bid, and was on track to have spent about a tenth of Bloomberg’s staggering total.
Thompson ran up huge margins in black and Hispanic neighborhoods, winning by a 3-to-1 margin in some districts.
He beat Bloomberg handily in predominantly black neighborhoods like Bedford-Stuyvesant in Brooklyn and Jamaica in Queens. He won Harlem and East Harlem easily, along with other heavily Hispanic districts in upper Manhattan and the Bronx.
By contrast, Bloomberg won easily on Staten Island, which has a much larger white population. He also fared better in Manhattan, particularly on the Upper East Side, where he lives.
The tiny margin could weaken his power and make his third term more difficult at City Hall, where Democrats poised to sweep into citywide offices indicated they would not shy away from disagreeing with the mayor.
“You’ll see a lot of strong voices as checks and balances,” said Democrat Bill de Blasio, who won the job of City Hall ombudsman Tuesday. “It will be a very different experience than what he experienced the last eight years.”
Bloomberg is just the fourth mayor to win a third term, after Fiorello La Guardia, Robert Wagner and Ed Koch.
Bloomberg was a Republican but left the party in 2007 to explore a presidential bid, a dream he eventually abandoned. For his third mayoral run, he ran again on the GOP and Independence Party lines.
While Bloomberg was often described as having every advantage in the race, including his estimated $17.5 billion fortune and consistently high approval ratings, his campaign did have to overcome some obstacles.
The mayor, who has close ties to Wall Street and development, was running for re-election at a time when finance and real estate were falling apart and those relationships were not necessarily seen as positives.
There are also the numbers — New York City leans heavily to the left, with Democrats outnumbering Republicans by a ratio of 5-to-1. Democrats were also energized by their party’s White House win in 2008.
And New Yorkers were angry that Bloomberg reversed his long-held support for term limits last year and persuaded the City Council, in a matter of weeks, to extend the law so he could run for a third term.
Thompson sought to stoke that resentment, but it was not enough.