Christine Quinn slips to 3rd in mayoral race, de Blasio surges to top, amNewYork-News 12 poll finds City Council Speaker Christine Quinn at City Hall. (Aug. 22, 2013) Photo Credit: Charles Eckert By EMILY NGO AND MATTHEW CHAYES August 29, 2013 11:00 AM Print Share fbShare Tweet gShare Email Council Speaker Christine Quinn has slipped into third place in the field of Democratic candidates for mayor, as New York City Public Advocate Bill de Blasio leads the field and former Comptroller Bill Thompson is within striking distance, according to an amNewYork-News 12 poll released Thursday. In the Republican race, Joe Lhota, the former MTA chairman, leads billionaire John Catsimatidis by a nearly 2-1 margin. De Blasio, buoyed by the city's most liberal residents for his opposition to the NYPD's stop-and-frisk practices and from a family-centric ad campaign, has 29 percent support among likely Democratic voters, according to the poll conducted by Penn Schoen Berland. Thompson has 24 percent and Quinn is third with 17 percent. "It's a momentum game," pollster Mike Berland said. "Clearly, de Blasio has momentum up, Quinn has momentum down and Thompson just hangs in there." Other polls conducted earlier in the campaign have had Quinn with a substantial lead and de Blasio as low as fourth place. If no candidate receives at least 40 percent of the vote on the Sept. 10 primary, the two top finishers will meet in a runoff on Oct. 1. Rounding out the field of Democrats in the amNewYork-News 12 poll is former Rep. Anthony Weiner with 10 percent, Comptroller John Liu, 5 percent and former Councilman Sal Albanese and Brooklyn minister Erick Salgado, 1 percent each. Undecided voters account for 13 percent of the sample. De Blasio has a substantial edge with voters who describe themselves as "very liberal," earning 45 percent of their support with Quinn in second at 19 percent. He beats Quinn -- the race's only woman -- with female voters, 29 percent to 19 percent. Thompson -- the only black candidate -- leads among African-American voters with 35 percent, but de Blasio is a strong second with 29 percent. The poll, conducted from Aug. 22-27, surveyed 600 likely Democratic primary election voters via landline and cellphone. It has a margin of error of plus or minus 4 percentage points. In the Republican primary, half of all likely GOP primary voters would pick Lhota over his two competitors, easily crowning him the party's nominee, according to the poll. The survey, of 400 likely Republican voters in all five boroughs, shows Lhota with 50 percent of support to Catsimatidis' 28 percent and George McDonald's 5 percent. Fifteen percent of those surveyed said they are undecided. Lhota's support is strongest among Manhattan Republicans -- with 66 percent to Catsimatidis' 18 percent there. The GOP survey has a margin of error of plus or minus 4.9 percentage points. Scroll down for detailed results from the amNewYork-News 12 poll of the Democratic primary race for New York City mayor. The poll, conducted from Aug. 22-27, surveyed 600 likely Democratic primary voters via landline and cellphone and has a margin of error of plus or minus 4 percentage points. Scroll down for detailed results from the amNewYork-News 12 poll of the Democratic primary race for New York City mayor. The poll, conducted Aug. 22-27, surveyed 600 likely Democratic primary voters via landline and cellphone and has a margin of error of plus or minus 4 percentage points.