Public Advocate and mayoral candidate Bill de Blasio emerges from a voting booth with his wife Chirlane McCray after voting in the New York City mayoral primary on September 10, 2013 in the Brooklyn borough of New York City. In recent polls by Quinnipiac University, de Blasio is now close to the 40 percent threshold he'd need to avoid a runoff in the Democratic primary. (Photo by Spencer Platt/Getty Images)

In days leading up to the Tuesday’s primary election, Democratic candidates in the hotly contested New York City mayor’s race made their final push to persuade voters and get out the vote.

A shift in polling from last week shows the public is still undecided. Public Advocate Bill de Blasio is leading among likely Democratic voters with 39 percent support, according the latest Quinnipiac University poll – not enough to avoid a runoff and a four-point drop from where he was a week prior. Former Comptroller Bill Thompson made gains over the week, going from 20 to 25 percent and City Council Speaker Christine Quinn rounds out third with 18 percent.

Former U.S. Rep. Anthony Weiner is in fourth place with 6 percent, followed by Comptroller John Liu with 4 percent.

“It looks as if Public Advocate Bill de Blasio couldn’t hold that 43 percent in a week when he was in the spotlight and he got walloped by everybody. His support by black voters slipped just enough to make a runoff possible. But he’s ever so close,” said Maurice Carroll, director of the Quinnipiac University Polling Institute.

Black voters are expected to comprise nearly 30 percent of the primary electorate in the race for New York City mayor. With 15 percent of black voters still undecided and 18 percent of respondents saying there is still a “good chance” they’ll change their mind before Tuesday, the candidates hit the trail hard to shore up support.

De Blasio backed by Belafonte in Brooklyn

With a relatively light schedule of just 13 stops between Saturday and Monday, De Blasio hit the trail to emphasize his message of making New York City affordable and ending stop-and-frisk. The frontrunner greeted prospective voters on the Upper West Side, in Washington Heights and East Harlem and across Brooklyn over the weekend.

At a rally Saturday, de Blasio responded to a remarks made by Mayor Michael Bloomberg in New York magazine regarding de Blasio’s use of his interracial family along the campaign trail. Alongside his wife and daughter Chiara, de Blasio called the mayor’s characterization of his campaign as racist “very unfortunate and inappropriate.”

“I think we have run a campaign about the ideas, about the issues, about how to move this city forward. I’m very proud of that,” de Blasio told members of the press. “I’m exceedingly proud of my family, and as you’ll know meeting every member of my family, they are each and every one strong and independent and make their own decisions.”

Perhaps the biggest de Blasio event, however, was on Sunday at Christian Cultural Center Church in Brooklyn, where de Blasio was joined by actor and activist Harry Belafonte, who has endorsed the candidate as a champion of the middle class. Belafonte also took the opportunity to blast Bloomberg as “blind” in response to his comments.

“He’s blacker than a lot of people I know,” Belafonte said of de Blasio.

Thompson makes marathon stops

Bill Thompson visited nine black churches throughout Brooklyn, Queens and Harlem on Sunday, including the historic Abyssinian Baptist Church where Congressman Charlie Rangel, a supporter, joined him. Thompson’s hectic weekend schedule also included appearances on hip-hop and Caribbean radio stations, a Jewish get-out-the-vote rally and yet another rally with numbers of the Congressional Black Caucus.

Monday, Thompson began off a 24-hour, five-borough, citywide tour that began with a visit to his childhood home in Brooklyn, then continued on a tour of small businesses in Brooklyn and was punctuated by a rally at City Hall. He told a cheering crowd that he expected to be triumphant by the close of polls on Tuesday.

“Over the next few hours, it’s the things that you do that will determine what direction this city goes in,” Thompson said. “Let’s knock on those doors, let’s make those phone calls, let’s reach out to people on the street.”

In all, Thompson made 32 stops between Saturday and Monday, far more than any other leading candidate.

Quinn questions polls

Christine Quinn also made a dash toward the finish line with 23 stops along the campaign trail during the same period. She kicked off the weekend’s events on Saturday with a visit to the House of Justice in Harlem for the National Action Network’s weekly action rally. She outlined her plan for increased jobs, more affordable housing, better education and policing.

Quinn spent most of her final hours in upper Manhattan and parts of Queens to remind voters that, despite polling, it could still be anyone’s race.

“I’ve seen a lot of history in this city and in national and other polls of polls not actually expressing where voters are at the exact moment when they’re going into the voting booth,” Quinn told reporters Monday in a break from handing out pamphlets near a Manhattan subway station. “We saw it at the last mayoral election, we saw it in the presidential election so I feel really good about how we’re doing heading into tomorrow.”

Polls will open at 6 a.m. and close by 9:00 p.m. ET.

Follow Donovan X. Ramsey at @iDXR