The Bradley Effect

With the presidential debates in the books and a commanding lead in the polls, Barack Obama appears to be coasting toward history. But a potential cakewalk makes for dull punditry, and politicos are abuzz over the last hurdle Obama must clear in his path to the presidency: a phenomenon known as the "Bradley effect."

The theory holds that voters have a tendency to withhold their leanings from pollsters when they plan to vote for a white candidate instead of a black one. In 1982, Tom Bradley—the African-American mayor of Los Angeles—ran for governor of California. On the eve of the election, polls anointed him a prohibitive favorite. But on election day, Bradley lost to his white opponent, Republican George Deukmejian. Some experts chalked up the skewed polling to skin color.

The notion was burnished by a series of subsequent elections in which black candidates saw solid leads shrink or vanish once voters cast their ballots. In 1983, Harold Washington escaped with a narrow win in Chicago's mayoral election after being projected a decisive victor. In 1989, Douglas Wilder held a nine-point lead on the eve of Virginia's gubernatorial election, and won by less than one percentage point. That same year, David Dinkins' 18-point lead in New York City's mayoral race evaporated in the voting booths, though he still eked out a nail-biter over Rudy Giuliani.

When Hillary Clinton edged Obama in this year's New Hampshire primary — despite data that showed Obama leading — some suspected the Bradley effect had crept back into play. "Since then," Democratic strategist Donna Brazile wrote recently, "pollsters and pundits alike have warned that Obama needs a six-to-nine point lead to overcome the so-called Bradley effect." In recent weeks, the New York Times and Washington Post have both run features examining the phenomenon.

But some analysts say there is little evidence the Bradley effect still exists—if it ever did. Among the more persuasive voices in this camp is V. Lance Tarrance, Jr. When he calls the Bradley effect "a pernicious canard," Tarrance speaks with some authority—he was the pollster for Bradley's opponent, George Deukmejian. Tarrance argues the effect was merely a result of bad data: the poll declaring Bradley a prohibitive favorite ignored Deukmejian's advantages among absentee and early voters. To give credence to a Bradley effect in this year's election, Tarrance argues, "is to damage our democracy, no matter who wins."

Other recent studies have added further doubt. Marshalling data from the 31 states with significant pre-primary polling this year, Nate Silver of the political website fivethirtyeight.com, argues it was Obama, not Clinton, who actually outperformed expectations in this year's primaries, by an average of 3.3%.

A study released by Harvard political scientist Daniel Hopkins offers a more nuanced historical view. Analyzing 133 gubernatorial and Senate races between 1989 and 2006, Hopkins says the Bradley effect—which he calls the "Wilder effect," after the Virginia governor—did exist, but petered out when racially charged issues were elbowed away from the political forefront: "As racialized rhetoric about welfare and crime receded from national prominence in the mid-1990s, so did the gap between polling and performance."

There is no question that racial bias is a powerful force to overcome and a slippery one to quantify. But with Obama propelled by panic over shrinking nest eggs and the wilting Dow, the Bradley effect may be this fall's paper tiger: an old theory re-heated by the media because there's not much left to talk about.