If this article makes some supporter of Proposition 8 work less hard or be less involved in the campaign for its adoption, they will be making a mistake. But it is true that, in many of these elections about the ending or preventing of gay marriage, the actual results surpass significantly the last polls in the direction of its passing. Proposition 22, for example, had election results 9 points higher than the final polls
When the latest Field Poll showed Proposition 8 losing by 17 points, skeptical supporters of the measure that would ban same-sex marriage in California invoked a phrase coined in the 1980s: “the Bradley effect.”
Named after the late Los Angeles Mayor Tom Bradley, an African American who lost the 1982 California governor’s race after polls showed him leading handily, the phrase refers to the tendency of respondents to lie to pollsters about issues of race.
The Bradley effect has been referenced in presidential polls this year as Sen. Barack Obama seeks to become the first black president. And it is also being used to describe possible disparities between polls taken on gay marriage measures and actual election results.
A new study of elections in 26 states – including California – found polls typically understate voter support for these measures.
“Because the media portrays gay marriages as being politically correct, people don’t want to be seen by pollsters as being intolerant – so they hide their views,” said Frank Schubert, campaign manager for the Yes on 8 campaign, which conducted the study.
As an example, Schubert cited Proposition 22, which California voters approved in 2000. The Field Poll showed the gay marriage ban – overturned in May by the state Supreme Court – was backed by 53 percent of voters right before the election. But when the votes were counted, 61 percent of voters supported the initiative.
The survey looked at measures banning same-sex marriage, dating back to the first such campaign in Hawaii in 1998. According to the study, surveys published by news media outlets before an election underestimated support for traditional marriage by an average of seven percentage points.
In only two of the 26 states did pre-election surveys accurately measure voter sentiment. Support for traditional marriage was underestimated in 23 states. In one state, Arizona, support dropped.
Schubert believes the Proposition 8 race is much closer than the Field Poll shows – a contention that’s not disputed by Steve Smith, who is managing the No on 8 campaign.
Mark DiCamillo, director of the Field Poll, said they could be right because some undecided poll respondents may not have been candid.
“It’s possible there could be certain segments of voters who in a similar way might be withholding their true judgment and saying, ‘I’m not sure’ when, in fact, they are going to be voting for the ‘yes’ side,” DiCamillo said.
In 1982, the last Field Poll showed Bradley, a Democrat, leading by five percentage points. Yet he lost to George Deukmejian, a Republican, by more than one point.
DiCamillo said a postelection analysis conducted by his organization found “nine out of 10” undecided respondents wound up voting for Deukmejian.
The analysis also cited other factors that worked against Bradley, including an aggressive GOP vote-by-mail campaign and a gun control measure on the ballot that increased Republican turnout.
But Patrick Egan, a professor of politics at New York University, analyzed the Yes on 8 study and concluded it overstated the gap between polls and election results because it did not adequately weigh undecided voters in the polls.
Egan said that while the share of supporters for banning gay marriage increased between the polling and the balloting, so did the share of opponents. But he does not deny the existence of the Bradley effect.
“Anyone who studies survey research will tell you one of the biggest problems we encounter is this notion of social desirability bias,” he said.
Poll respondents generally overreport that they vote, for example, he said. But they underreport drug use and abortions, based on vital records.
“We might expect that as it becomes less acceptable to express anti-gay attitudes, a Bradley effect of sorts would kick in,” Egan said.
The central question, he said, “is to what extent are these attitudes becoming so unacceptable that people would be reluctant to state them to a researcher.”
Egan said a careful analysis of polling data and election results indicates that if the Bradley effect exists with regard to same-sex marriage, “it’s small and certainly not getting bigger over time.”
To support his contention, Egan reanalyzed the data compiled by the Yes on 8 campaign – and did not allocate undecided poll respondents to the “oppose” category.
He concluded that since 1998, the gap between poll support for marriage bans and election results has averaged only 2.2 percentage points. In 2006, the gap declined to just three-tenths of a point in the seven states holding initiatives for which data were available.
Egan, citing a study by Daniel Hopkins, a Harvard University postdoctoral fellow, also believes the Bradley effect may have vanished as it relates to African American candidates.
Hopkins examined 133 gubernatorial races from 1986 to 2006 and concluded that the effect vanished in the early 1990s.
This year, according to Hopkins’ analysis, Obama slightly outperformed his poll numbers during the primaries.
Conversely, in two precedent-setting 1989 races for African Americans, Douglas Wilder narrowly became governor of Virginia and David Dinkins mayor of New York after final polls showed them with double-digit percentage leads.
As for the poll showing Proposition 8 losing by 17 points, Egan said “any polling process is going to produce a range of estimates. Some will be closer to the eventual results, and some will be outliers.”
“Given that this is a really huge margin, I wouldn’t be surprised if that was an outlier,” he said.
Another recent poll, conducted by SurveyUSA for a group of television stations in California, found Proposition 8 ahead by five points, 47 percent to 42 percent.
SurveyUSA’s telephone polls are conducted by robots, Egan said, which in the case of Proposition 8 minimizes the Bradley effect.
“If there were ever a way of being relatively free of social desirability – or political correctness, as some people call it – it’s a robot,” Egan quipped.
Or, he said, the difference between the findings in the Field and SurveyUSA poll could be ascribed to methodology.
The Field Poll was conducted last month – before campaign ads started airing – while the “robo-poll” was conducted this past Saturday and Sunday. Both sides are expected to spend millions on television ads.
“A lot could change in (four) weeks – including polls,” Egan said.