LOS ANGELES (MarketWatch) - It's a question that comes up whenever anyone of African-American descent is a candidate for office, and this year is no exception: is the so-called "Bradley effect" going to play a role in the 2008 presidential race?

Many pollsters doubt it, and think there's an even more fundamental question to be asked - whether there ever was such a phenomenon. If there was, they seriously doubt that with all the time that has passed since the late Tom Bradley lost a close gubernatorial race in California 26 years ago - despite being ahead in late polls - that it will play a significant role when the time comes to pull the lever for Barack Obama or John McCain Nov. 4.

"I think the evidence is very mixed on whether the [effect] occurs," said Frank Newport, editor-in-chief of the Gallup Poll. "There may be a rare effect, but that doesn't affect our surveys."

Not even Rev. Al Sharpton, caught briefly at the Democratic National Convention in Denver in August, thinks it will play much of a role.

"We're always concerned, but I have no particular concerns about the Bradley effect," Sharpton said. "I think [voters] have [evolved]. We'll see how far, but I think they have."

One-third negative

To be sure, the question of race is bound to rear its head again, at least in some measure. A recent poll conducted by Associated Press and Yahoo News said that one-third of white Democrats harbor at least some negative views toward blacks.

As a result, several million voters could turn away from Obama because of his race, the poll said, with as much as 6% to 7% of the electorate picking another option for president purely based on that issue.

With the presidency on the line, voters with anti-black sentiments may feel determined to send Obama down to defeat, reasoning that too much is at stake for them to stray from past voting practices. Obama, whose father was Kenyan and mother was white, has a lead over McCain that is slowly growing, and is anywhere from 7% to 8%, according to various estimates.

The central question, however, is whether voters will be truthful when pollsters ask who they plan to pick in November, a key element of the Bradley effect. It reasons that some self-conscious voters were afraid to reveal their true sentiments when asked by pollsters for whom they would vote.

That very question causes some to pause and reflect: why would voters lie to anonymous pollsters? Why wouldn't voters simply just say they support the white candidate without further explanation?

"I don't know," said Gallup's Newport. "That's why I don't think there's any evidence to support it."

1982 race

The Bradley effect got its name when the African-American mayor of Los Angeles ran against Republican George Deukmejian in the state's gubernatorial race in 1982. In polls just prior to Election Day, Bradley was shown to have a comfortable lead of more than 5 percentage points.

It seemed a foregone conclusion that Bradley, who died 10 years ago this last Monday, would become the first African-American to win a governor's race in the nation. Newspapers and magazines reportedly fashioned covers touting the milestone, but they jumped the gun.

When the polls closed on Nov. 2 of that year, it was determined that Bradley lost to Deukmejian by less than 100,000 votes out of nearly 7.9 million ballots cast.

Afterward, there were concerns that voters misled pollsters by insisting they would vote for Bradley in surveys, but changed their tune when push came to shove in the voting booth.

Mark DiCamillo, now the director of the San Francisco-based Field Poll, one of the most widely used California polling institutions, remembers the incident well. Field had projected Bradley to win by at least five percent over Deukmejian.

"I'd been at Field for only two years. I thought I was going to be fired," DiCamillo said.

Small role

The Field Poll wasn't alone in predicting a relatively easy Bradley victory. And as it turned out, race played only a small portion in Bradley's defeat, if any, DiCamillo said. Field did a white paper dissecting what happened three months after the fact, and discovered that if voters had concealed their true intentions, it might have only affected 1 or 2% of the vote at the most.

It was more a perfect storm of activity that doomed Bradley in the voting booth, all of which worked against him, DiCamillo said. That's unusual in that mitigating factors tend to offset each other in elections; in this case all worked against one candidate.

First, there was a handgun initiative on the ballot in that election, bringing out an unusually heavy Republican vote in the election, he said. There also was a lower-than-usual turnout from minority voters.

Another factor that puts holes in the Bradley effect theory is that he won the race at the polls. But an unusually high number of absentee ballots - with more than 300,000 or nearly 60% - were cast for Deukmejian. A relaxing of rules on absentee voting made for an unpredictably high number of Republicans casting ballots away from their precincts.

Had any one of those factors not played a part in the election, Bradley would have emerged victorious, Di Camillo contends.

"It was a classic upset, with eggs on pollsters' faces up and down," he said.

Other examples

Still, some pollsters believe the Bradley effect was real. African-American Douglas Wilder barely squeaked out a victory in Virginia's 1989 gubernatorial race by less than half a percentage point despite holding a nine-point lead just before the election. The phenomenon actually is sometimes called the Wilder effect.

There are other examples, such as Harold Washington's four-point victory in the 1983 Chicago mayoral race despite a double-digit lead in polls, and David Dinkins' two-point victory over Rudy Giuliani in 1989 to be New York's mayor despite a 14-point margin in late polls.

"People don't like to admit they're prejudiced," said Maurice Carroll, director of the Quinnipiac University Polling Institute. He agrees, though, that the electorate has evolved to the point where any such effect should be minimal.

Indeed, a number of multi-racial contests since those races seem to indicate a minimal racial impact. Louisiana Gov. Bobby Jindal, an Indian-American, was thought to have lost a 2003 runoff in the gubernatorial race due to the Bradley effect, but he ended up winning four years later by a wider margin than polls showed.

Harold Ford, an African-American, lost by a slim margin in the Tennessee U.S. Senate race to white candidate Bob Corker, but exit polls showed that white voters who actually cast ballots for Ford were close percentage-wise to what earlier polling showed.

Some pollsters believe that the electorate has evolved to the point where there could be a "reverse Bradley effect." Young voters who could show up en masse in support of Obama may not be getting counted in polls, particularly if they use only cell phones and don't have land lines.

"What we have to do is make sure we have enough young people in our polls," said Scott Rasmussen, whose firm Rasmussen Reports conducts daily polling on the presidential race, concurs. He adds that younger voters generally aren't harboring the same feelings about race as earlier generations.

"My own sense of the campaign is we're not going to see a huge Bradley effect," he said. "Of course it's possible. And we won't know until Election Day."