The Pew Research Center is normally one of the most reliable pollsters – they use sound sampling techniques, generally have a robust sample size, and in 2004 came very close to nailing the final election results. Thus it is with some interest that I looked at their final election survey, which was released today. Its headline read: “Obama leads McCain 52-46 in campaign’s final days.” However, if you go beyond the headline to read the actual survey, you find that in fact the survey indicates that Obama is up 49%-42% over McCain, with 7% undecided, and another 2% voting for Nader or Barr. How did they arrive at the figures trumpeted in the headline? By deciding to allocate the undecideds between the two candidates. In this case, they assigned McCain 53% of the undecideds, and Obama 47%. Presumably they did so by looking at the same demographics that I noted in an earlier post – that undecideds are slightly more white, less affluent, less educated and more likely to be women – and therefore were more likely to vote for McCain. We will know in less than 72 hours whether that allocation was consistent with the final vote.
In the meantime, what does the Pew survey tell us if the undecideds remain unallocated? The most important finding is that Obama is in the lead by 7%, more than the margin of error in this poll (2.5%). That’s the good news for Obama. The good news for McCain is that this represents a net gain for McCain of 8% since the last Pew poll from 5 days ago – a pretty substantial gain in that time period (keeping in mind that this may simply reflect random variation across the two polls). Interestingly, that gain was due to a combination of slippage in Obama’s support and increases in McCain’s. More interesting still, the number of undecideds did not go down in this period.
Where did McCain make his gains, if not among undecideds? Primarily among independents, especially middle-income voters and women. Most notably, he gained 16% among independent women voters, and about 8% among young (18-29) independents since the previous poll.
Keep in mind that this is only one poll (I will deal with the latest tracking polls in a separate post). Moreover, even with McCain’s latest gains, Obama remains comfortably ahead with less than 72 hours until election day. Unless other polls indicate similar trends, Obama has little to worry about. For McCain to close this gap he would need to win all the undecideds while keeping Obama below the magic 50% mark. But from McCain’s perspective, it is better to be behind 49-42, than to be behind 52-46. even though the latter figures make the race appear to be closer. As long as Obama hasn’t broken the 50% threshold, there is a glimmer of hope.
The Pew poll reminds us, then, that some polls showing Obama at more than 50% do so by pushing “leaners” or, in Pew’s case, deciding to allocate the undecideds. As always, read the fine print.
In thinking about the debate on your blog and elsewhere about undecided voters, I’m wondering what evidence is there to suggest that those who remain undecided at this point will turn out to vote? In one of the articles you cited on your blog recently, Michael McDonald, a political scientist from George Mason University argues that, “If they can’t distinguish between the candidates at this stage, the question is if they will vote.” . This is a valid argument on the surface. However, our figures for the number of undecided voters come from polls, which at this point all use likely voter models. This means that for some reason, pollsters have determined that these undecided voters are in fact likely to vote. How?
Only a portion of the voting age population actually votes. I would expect more people to be undecided in the total voting age population than in the population of likely voters. This assumes that being interested in a candidate makes you more likely to vote (not always the case, given the historically poor turnout among the youth). This expectation is also plausible, however, because the demographics of the current undecideds mirror some of the demographics that are less likely to vote in general (in this case the less educated). As a rough measure of my theory, I looked at the last polling period in which several pollsters were still using registered voter models. My hypothesis was that undecided voters are less likely to vote, and therefore, we would see a smaller number of undecideds in polls using LV than RV. In the polling period ending 10/09/08 (all data from realclearpolitics.com) 3 polls used RV models, and 4 used LV models. The average % undecided in the LV polls was 7.75%, while the average % undecided in the RV polls was 10%. This can’t really tell us much because of the differences between pollsters, particularly whether or not they push undecideds to make a decision, but it may suggest that undecided voters are less likely to turn out. None the less, many do turn out, and pollsters continue to include undecided voters in their LV models on the assumption that some will come to a decision by Election Day.
Can the same determinants be used to measure voter likelihood among undecided voters as are used with decided voters? If undecideds are less attuned to politics and less knowledgeable about the race, are they also likely to be less knowledgeable about where their polling place is? Are the likely to have voted before? Are these people counted simply because they claim to be likely to vote? Do the same people hold out to the last minute every election?
Check out MiddBlog’s community team liveblog coverage of Nov. 4 Election Day and Night: http://www.midd-blog.com.
Jesse – Great question. Most pollsters have a series of questions that have proved reliable in the past in differentiating likely voters from those who are not likely to vote. Having made this initial cut, they then assume that all the likely voters will vote. In truth, not all of them do. The discussion that Bert and I had regarding undecideds gets to the heart of your question. Bert and I agree that undecideds, based on past research, can be treated as a distinct voting group. I’ll let Bert add his two cents worth, but I think that in the end the undecideds do not vote in purely random fashion, but instead generally react to the same context in roughly similar fashion to those sharing similar demographic characteristics. Because of lower information and interest in the election, they may come to their decision more slowly. But I agree that a subset of them may not vote at all.