I’ve done a simple analysis that speaks to this question. Using the 1972-2008 American National Election Studies, I examined only white voters and modeled presidential vote (excluding third parties) as a function of three factors:
* Identification with a party, which is coded in 7 categories ranging from strong Democrat to strong Republican. This is a conventional measure in political science.
* Self-reported ideology on the liberal-conservative spectrum, which is also coded in 7 categories ranging from strong liberal to strong conservative. This is also a conventional measure, although hardly the definitive measure.
* A measure of affect toward blacks. Beginning with the 1972 survey, respondents were asked to evaluate various groups on a 1-100 “feeling thermometer,” where 1 signifies very cool feelings and 100 very warm feelings. I subtracted affect toward blacks from affect toward whites. Thus, people with higher scores evaluated whites more favorably than blacks. (Computing the difference between evaluations of whites and blacks helps deal with scale incomparability across respondents; see Lee’s felicitously titled article.)
(Nerdy details: Each factor is scaled 0-1. Presidential vote is coded 1-Republican and 0-Democrat. The model is a logit model, with survey weights. This is particularly important in 2008, when the ANES intentionally sampled a larger number of blacks.)
Yes, this is a simple model. Yes, I could control for other things. Yes, it’s not a perfect measure of prejudice. (And so forgive me the title of the post. I’m just trying to draw some attention amidst the other interesting stuff on people’s RSS feeds.) To summarize: this is a blog post, not a journal submission.
Below I plot the coefficients and confidence intervals from a model in each presidential election year. Larger values mean a stronger relationship between the factor in question and presidential vote. If the confidence interval does not cross 0, then the coefficient attains conventional levels of statistical significance.
The results show the increasing effects of both party identification and ideology. These are familiar findings (see, e.g., here).
Affect toward blacks had a statistically significant impact in 1972-92, but its impact was much closer to 0 in 1996 and 2000. Its effect was larger in 2004 than in the two previous elections, although not statistically significant. In 2008, however, its effect was larger still and statistically significant.
What does the 2008 effect, substantively speaking? It means that, controlling for party identification and ideology, the more negatively a white person evaluates blacks, relative to whites, the more likely they are to vote for McCain. For example, a white person who calls him or herself an independent and a moderate and evaluates whites and blacks equally would have a .51 probability of voting for McCain. A person who is an independent and a moderate, but who evaluates blacks 20 points lower than whites on the feeling thermometers, would have a .57 probability of voting for McCain — a 6 point increase.
That is a hypothetical effect at the level of an individual voter. What about at the level of the electorate as a whole? To simulate this effect, I calculated Obama’s expected share of the vote based on predictions from the model above. As before, I am focusing on white voters. Then I simulated his share of the white vote if everyone who had a less favorable view of blacks, relative to whites, were magically transformed into someone with equivalent views of blacks and whites. So what would happen to Obama’s vote share among white voters in this scenario, relative to reality?
It would have increased by 1 percentage point. That’s it.
Sound small? This is because those whose affect toward blacks changed in my simulation may have been predisposed to vote for McCain because of party or ideology. In sum, there are relatively few voters who are both negatively disposed toward blacks and not already strongly committted to a candidate for other reasons.
This analysis buttresses Charles Franklin’s analysis of a pre-election poll, which I linked to in late October. He also found small aggregate effects. Neither of our analysis speaks at all to Electoral College votes, which would require separate analyses of survey data in individual battleground states.
Let me be clear: this analysis is not the final word. Not at all. By any stretch. At all. Seriously. But I am willing to bet that truly sophisticated analyses will show something similar: a significant individual-level effect of racial prejudice on presidential voting in 2008, but not necessarily large aggregate effects on the actual outcome of the election.