Why there is no Bradley effect for Obama

The ‘Bradley effect’ is a supposed bias in opinion polls whereby black candidates appear to have more support than they actually do, because voters don’t like admitting their racial prejudice (or even being perceived as someone who votes on grounds of racial prejudice). It’s named after Tom Bradley, Democratic (and black) candidate in 1982 to be California’s Governor, who lost the election despite an exit poll putting him well ahead.

But the Huffington Post’s man from the Bradley campaign says that it was just a duff exit poll: it also falsely showed a win for the Democrats’ (white) senatorial candidate (hat tip to Danny).

And Kate Zernicke looks at data from a number of elections – including this year’s Democratic primaries – and finds no convincing evidence for such an effect.

Here’s my theory on why not.

People are likelier to lie to pollsters when they might feel ashamed or embarrassed to admit their true views. But this skews voting intention polls only when the candidate the voter really supports is widely seen as shamefully bad – not just when the other candidate is in some quarters opposed for shameful reasons.

When general questions are asked about race and willingness to support, the 6% or so who admit that they would not vote for a black candidate is certainly an underestimate. And as for the specific election that now looms, I think Obama’s personal ratings are probably exaggerated by the polls, but that voting intention figures are pretty much entirely free of racial bias.

Polls consistently find that about 55% of voters have a favourable opinion of Obama and about 35% an unfavourable opinion. I’d expect that there is a bias here, with people worried that their own dislike of media darling Obama could be seen as racially motivated (whether it actually is or not).

But the same polls find McCain’s ratings at about 50% favourable to 40% unfavourable. This is a separate question to that about Obama, so there’d be no racial bias here (unless people are afraid of being seen as anti-white?).

So there it is: plenty of people (say they) think well of McCain. More, in fact, than say they’ll vote for him over Obama. But as McCain is far from being despised, then there’s no shame in admitting to supporting him. And if 50ish% are unashamed to say they like him, then there’s no bar to their saying they’ll vote for him.

What’s more, except for a few noxious emissions around the Republican fringe, the McCain campaign has avoided playing the race card – so there’s no significant public narrative of race being the driving force in people supporting McCain over Obama.

It’s a certainty that Obama has forfeited some support due to prejudice. But there’s no reason to think the polls haven’t picked this up: there are plenty of ‘legitimate’, non-racial reasons that swing voters might have for preferring McCain to Obama: experience, ‘toughness’, his war record and any number of policy issues.

And it’s possible, of course, that the polls are wrong for other reasons. We’ll find out soon enough.