0. Intro Eight million residents. Four million voters. But when the polls open in New York City for the mayoral primary, fewer than 800,000 Democrats – and fewer than 80,000 Republicans – are expected to vote. A few voting groups play an outsize role in the outcome, simply by contributing to candidates and showing up to vote. The Democrats considered most likely to vote – based on their behavior in past elections – are often referred to as “prime voters,” and they are aggressively courted by campaigns. Here are key voting blocs that are likely to wield the most influence in the 2013 Democratic primary. Where the electoral power lies in the 2013 New York Democratic mayoral primary. Start the tour Scroll to read

1. Central Brooklyn This predominantly black area is home to nearly 1 in 10 of the city’s Democratic prime voters – those who voted in both of the most recent mayoral primaries – and, as a result, holds huge sway in city elections. The area has also been particularly affected by the New York Police Department’s stop-and-frisk practice – officers stop residents here more often than anywhere else – and the policing tactic has become a huge issue in the race for mayor. William C. Thompson Jr. did very well here in the 2009 general election, when he was the Democratic nominee, but this year he faces competition in these neighborhoods from Bill de Blasio, John C. Liu and Anthony D. Weiner. Prime voters: 19,715iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $556,000Contributions to Democratic mayoral candidates since 2001.i

2. Chelsea-The Village These neighborhoods – active, politically generous, mostly liberal and white, and historically the center of the city’s gay life – are a stronghold for Christine C. Quinn, who represents much of the area on the City Council. Ms. Quinn raised more money here than the other candidates combined, and should do well on Primary Day. But all of her opponents are campaigning here too, including the peripatetic Mr. Liu, even though he found few votes among this constituency during his race for comptroller in 2009. Prime voters: 14,395iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $5,204,000Contributions to Democratic mayoral candidates since 2001.i

3. Upper West Side Residents here are the city’s most reliable voters, and among the most liberal in the country. The neighborhood is home to a large Jewish population. Many residents are affluent and generous political contributors. Ms. Quinn leads in contributions from this neighborhood, raised largely in 2009, when she first contemplated a bid for mayor. Mr. de Blasio did well here in his 2009 race for public advocate. Prime voters: 13,952iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $5,146,000Contributions to Democratic mayoral candidates since 2001.i

4. Dominicans In neighborhoods in northern Manhattan and the west Bronx where Dominican-Americans predominate, participation in city elections is high. Mr. Thompson carried about two-thirds of the vote against Mayor Michael R. Bloomberg here in 2009, and he has made the most appearances here this year. Mr. Liu, who won only about 40 percent of the vote here in the 2009 primary for comptroller, and Erick Salgado, a mayoral candidate who was once a missionary in the Dominican Republic, have also been actively campaigning here. Prime voters: 12,695iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $357,000Contributions to Democratic mayoral candidates since 2001.i

5. South Bronx This heavily Puerto Rican area has a lot of residents, but their impact on city politics is limited by low election turnout. Dominicans, blacks and a growing population of Mexicans and Central American immigrants also live here. Ms. Quinn has made more campaign stops here than her opponents. Mr. Thompson has endorsements from well-known Hispanic politicians in the borough. Prime voters: 11,057iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $421,000Contributions to Democratic mayoral candidates since 2001.i

6. Queens Blacks Middle class voters in southeast Queens, many of them African-American homeowners, make up Mr. Thompson’s strongest constituency. Although recent polls say only 22 percent to 39 percent of black voters support him, polls underpredicted his vote among blacks in 2009, when he won 80 percent of the vote here against Mayor Bloomberg. Prime voters: 8,901iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $183,000Contributions to Democratic mayoral candidates since 2001.i

7. Brownstone Brooklyn This area is liberal, politically active and affluent, but not as rich as Manhattan. Mr. de Blasio lives in Park Slope and is popular, winning easily here in the 2009 primary for public advocate. Ms. Quinn raised a lot of money here in 2009, but Mr. de Blasio easily beat her in contributions this year. Mr. Weiner did well here in the 2005 Democratic primary for mayor. Prime voters: 8,881iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $1,678,000Contributions to Democratic mayoral candidates since 2001.i

8. Upper East Side Ms. Quinn earned her standing as the candidate of the establishment partly because of her prodigious lead in raising money in this rich, mostly white area. It is the political-money capital of the city, but many residents register as Republicans, limiting the neighborhood’s impact in a Democratic primary. Mr. Liu is not popular here, raising dimes to everyone else’s dollars. Prime voters: 8,057iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $13,130,000Contributions to Democratic mayoral candidates since 2001.i

9. Central Harlem The predominantly black population here has historically had high levels of turnout in city elections. Mr. Thompson, who has endorsements from the Harlem power brokers Charles B. Rangel and David N. Dinkins, the city’s first black mayor, did very well here in the 2009 general election, as did Mr. Liu. Mr. de Blasio did not, garnering only 25 percent of the neighborhood’s votes in the public advocate primary that year. Recent polls have suggested that Mr. de Blasio is generally doing well among black voters this year, and this could be a key test. Prime voters: 7,188iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $422,000Contributions to Democratic mayoral candidates since 2001.i

10. Northeast Bronx The northeast Bronx is another area with a predominantly black population, similar to southeast Queens, but with slightly lower income and turnout. This area was one of the best in the city for Mr. Liu when he ran for comptroller. C. Virginia Fields, an African-American woman then serving as Manhattan borough president, lost this area to Fernando Ferrer, the Bronx borough president, in the 2005 Democratic primary for mayor, but Mr. Thompson won decisively here in the 2009 general election. Prime voters: 5,470iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $121,000Contributions to Democratic mayoral candidates since 2001.i

11. White Catholics New Yorkers of Italian, Irish and Polish descent are concentrated in enclaves on Staten Island; in Middle Village and Howard Beach in Queens; in Bay Ridge, Brooklyn; and elsewhere. These groups once dominated Democratic city politics, but their impact has receded as more and more have registered as Republicans. Mr. Liu ran first in heavily white Catholic neighborhoods in 2009. And Mr. Weiner ran exceptionally well in these areas in the 2005 Democratic mayoral primary. Prime voters: 5,287iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $2,349,000Contributions to Democratic mayoral candidates since 2001.i

12. Chinatowns Mr. Liu has found voters, and contributors, in Asian neighborhoods like Chinatown in Manhattan, Flushing in Queens and Sunset Park in Brooklyn, where candidates have not done well previously. His fund-raising in the mayoral race is a barometer: He has raised four times as much here as any candidate for mayor in the last five elections. Mr. Liu’s ethnic base may be the only unassailable one – his opponents have hardly visited these areas. Prime voters: 4,851iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $1,303,000Contributions to Democratic mayoral candidates since 2001.i

13. Queens Hispanics Despite its large population, this community is politically inactive. Many residents are noncitizen immigrants who are not eligible to vote – there are only about half as many prime voters per capita here as there are in black neighborhoods. Mr. de Blasio has not run well here in the past. Mr. Thompson won 55 percent of the vote here in the 2009 general election against Mr. Bloomberg. But this is one of the predominantly Hispanic areas where Ms. Quinn, with help from some Hispanic groups, hopes to do well. Prime voters: 4,799iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $411,000Contributions to Democratic mayoral candidates since 2001.i

14. Non-Orthodox Jews This group, represented in Forest Hills in Queens, and Riverdale in the Bronx, was a key constituency for former Mayors Edward I. Koch and Rudolph W. Giuliani and for Mr. Bloomberg. Residents of these areas reliably participate in Democratic primaries, and these neighborhoods are often a significant source of campaign contributions as well – although this year much of the political spending in Forest Hills is from Asian-Americans giving to Mr. Liu. Prime voters: 4,776iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $1,176,000Contributions to Democratic mayoral candidates since 2001.i

15. Bushwick-Cypress Hills This area on the Brooklyn-Queens border has many Puerto Ricans, as well as other Hispanics, but it has a limited impact in city elections because of low voter participation. Ms. Quinn made several visits here in August. Incomes tend to be higher here than in Hispanic neighborhoods in the Bronx. Prime voters: 4,132iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $153,000Contributions to Democratic mayoral candidates since 2001.i

16. Spanish Harlem This long established Puerto Rican neighborhood has more prime voters per capita than most other Hispanic areas. Prime voters: 3,646iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $141,000Contributions to Democratic mayoral candidates since 2001.i

17. Hasidic Jews This group has been known to vote with near unanimity, often for Republicans in general elections. Hasidic precincts in Borough Park, Williamsburg and Crown Heights in Brooklyn were Mitt Romney’s best in the city during the presidential election of 2012. But many Hasidic Jews register as Democrats to have an impact on city elections, and Mr. de Blasio reaped a bumper crop of votes in 2009 in Borough Park, once part of his City Council district. This year, however, Ms. Quinn has raised more money here. Prime voters: 3,503iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $1,119,000Contributions to Democratic mayoral candidates since 2001.i

18. Orthodox Jews Areas where this community is concentrated, like Ocean Parkway in Brooklyn, are the most politically generous outside of Manhattan. Mr. de Blasio raised a lot here early in his campaign, but that has slowed to a trickle. Mr. Weiner was successful in fund-raising here in 2009, and he got a lot of votes in this area in the 2005 primary. But recently, Ms. Quinn has been raising more than everyone here. Prime voters: 2,940iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $2,009,000Contributions to Democratic mayoral candidates since 2001.i

19. West Indians Many West Indian blacks live in East Flatbush, Brooklyn. A lot of education, health care and government workers live here, which means union members. It is also part of the stop-and-frisk nexus, a police precinct in which the practice was common. Voter turnout is somewhat lower than in other black neighborhoods. Prime voters: 2,782iThe number of people who voted in the Democratic mayoral primaries in 2005 and 2009. Money raised: $72,566Contributions to Democratic mayoral candidates since 2001.i