Weiner jolted the race in May when he ended his self-imposed political exile that began when he resigned from Congress in 2011 after sending lewd online messages to women who were not his wife. He led the polls for nearly a month only to tumble when it was revealed that he had continued to send the explicit messages in the months after leaving office.
The comptroller, John Liu, is bidding to become the city's first Asian-American mayor but has been dogged by a fundraising scandal. He has been polling in the single digits.
Republicans will look to continue an improbable winning streak. Though outnumbered by Democrats in the city 6-to-1, the GOP has won the last five mayoral elections. (Bloomberg was an independent running on the Republican line four years ago.)
Joe Lhota, the former MTA chairman who received acclaim for steering the transit agency through Superstorm Sandy last fall, has led the polls all campaign. A former deputy mayor to Rudolph Giuliani, Lhota has pledged to maintain the city's record low crime rates.
His primary challenger is John Catsimatidis, a billionaire grocery store magnate who has unleashed a series of blistering attack ads on Lhota, including one that mocks the front runner for dismissing Port Authority police officers as "mall cops." Catsimatidis has spent more than $4 million of his own money on the race, but that's a far cry from the $102 million Bloomberg spent four years ago.
Bronx voter Michael Horan, 59, a retired teacher who voted for Catsimatidis, asserted that Lhota "caused a transit strike. He got the fare up sky high and then he left." Horan also referenced the "insulting" depiction of "mall cops."
Bronx voter Fabian Feliciano, a 43-year-old city social services worker called Lhota the best all-around candidate, adding, "He'll really take care of the middle class."
Also Tuesday, ex-Gov. Eliot Spitzer will be trying to make a political comeback in the Democratic primary for city comptroller. Seeking to rebuild a political career devastated by a prostitution scandal, Spitzer is taking on Scott Stringer, Manhattan's borough president.
Polls close at 9 p.m. Experts do not believe turnout will be high.
Associated Press video journalist Ted Shaffrey and Associated Press writer Jim Fitzgerald contributed to this report.
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