Bounce or Bradley?

September 10, 2008
Posted by Jay Livingston

The first poll released after the Republican convention (USA Today/Gallup) showed McCain going from even or even 5-6 points down to a 54-44 lead. Subsequent polls have the race still even, and the USA Today/Gallup poll may be a statistical anomaly. Even if it’s accurate, Democrats are hoping it reflects a post-convention bounce which will, like most such bounces, diminish with time.

But there’s another explanation that should be more unsettling for Democrats: the disappearance of the Bradley effect – the inaccuracy of polls when voters claim to be undecided rather than say they will vote for the white candidate over the black candidate.

For example, in the New York City mayoralty race of 1989, an African American, David Dinkins had defeated Ed Koch in the Democratic primary and was running against Rudy Giuliani. Polls taken shortly before the election showed Dinkins ahead by 15 percentage points or more. He won by two.

Adam Berinsky, guest blogging at The Monkey Cage, puts it this way:

In that election, the preferred candidate of older Jewish Democrats (or, as I like to call them, Mom and Dad), Ed Koch, lost a contentious Democratic primary to David Dinkins, who is black. Considering that many older Jewish Democrats had never in their life voted for a Republican candidate, a vote for Giuliani in the general election could be seen as nothing but a vote against Dinkins. Indeed among Jews over 50, 30 percent claimed that they didn’t know who they were going to vote for a week before the election, even though 93 percent said they would definitely cast a vote . . . . These are the precise circumstances where we would expect to see the polls perform poorly – and they did.

I prefer the Dinkins example to that of Tom Bradley (California, 1982) or Douglas Wilder (Virginia, 1989) because it had a sequel that adds to our understanding of the Bradley effect.

In 1993 Dinkins again ran against Giuliani, this time as an incumbent. In that election, unlike 1989, the pre-election polls were very accurate. One explanation for the discrepancy in the performance of the polls between 1989 and 1993 is that in 1989, Democratic voters could not openly oppose Dinkins without appearing to be racist. By 1993, however, they could oppose Dinkins because in the intervening 4 years he had established a poor record of performance.

In other words, racism was looking for a rationale. Once it had that rationale, it no longer needed to stay in the “undecided” closet.

Could something similar have been happening in the current Presidential campaign? Let’s assume that there are some voters who are reluctant to vote for Obama because of his race. Maybe they don’t even admit that to themselves, and they certainly don’t admit it to pollsters. Instead, they think and say, “I’m not sure. I don’t really know enough about the guy.” Then they see McCain and Palin at the convention, they see the clips on the news. They like what they see, or at least they see nothing to dislike. Now they have the “information” to justify their decision, and when the pollsters call, they can honestly say they’re for McCain.