Because I have been giving election talks with more frequency of late, I haven’t been able to post nearly as often as I would like. In giving those talks, however, I am reminded (and I remind my audiences!) that, once again, looked at in the aggregate, the structural-based political science forecast models issued by Labor Day (or earlier) have proved remarkably accurate. For those new to this blog, the median forecast of the 11 political science forecast models that I reviewed in previous posts gave Obama 50.6% of the two-party vote. The average forecast from those 11 models gave Obama 50.3% of the two-party vote. Remember, this was before the debates, the tax returns, the “gaffes”, and all the other events cited by various pundits as potential game changers. As of today, that aggregate median forecast (those who attend my talks will remember that the aggregate median forecast provides the basis of my election prediction) from two months ago looks like it will come very close to hitting the final Obama popular vote share squarely on the head if the national tracking polls are to be believed. This is no mean feat, in my book, and it is a reminder that political scientists have developed a decent understanding of the factors that drive presidential election outcomes. It is reassuring that this election cycle has proved remarkably unsurprising in terms of its likely outcome.
Of course, while those structural models may be correct in predicting this race would essentially be a dead heat, they don’t tell us who is going to win, which is what most people want to know. At this point, five days before the election, you are better off looking at the polls – state and national – which are probably going to be more accurate than structural models devised several months ago in predicting the winner (even if they are going to be far less useful in understanding why Obama, or Romney, won). Several political scientists (and others) have developed Electoral College forecast models based on state-level polls, in contrast to the structural models which ignore polls entirely. I present four of these state-based projections here. (Readers will remember that if I can’t see what goes into a prediction model, I don’t bother following its projections. That’s a basic tenet among academics, and it explains why I ignore some of the more highly publicized state-based forecast models. )
As you can see, all four of these forecasts show, as of today, that Obama is likely to win the Electoral College vote, based on state-level polls. This has led pundits at some sites, like this one at Mother Jones, to suggest that if all these prognosticators are predicting an Obama victory, it must be so. But it would be a mistake to treat these forecasts as independent assessments. In fact, all rely on the same set of state-level polls, and if the polls are wrong for some reason, all of the projections will be off as well. Moreover, as several commentators have noted, the national tracking polls tell a slightly different story. Consistent with the structural forecast models, they indicate that this race is actually a dead heat. Indeed, some pundits, like Pollster.com’s Steve Lombardo, are convinced that the national tracking polls indicate that Romney is poised to win the national popular vote. Lombardo writes,” Our current estimate (which we will update next Tuesday morning) suggests that Romney will capture 51 percent of the popular vote to Obama’s 48.5 percent. The trend line-based on 26 national polls conducted over the last 30 days –is both unmistakable and virtually unassailable.”
If Lombardo is right, there is virtually no chance that Obama will win the Electoral College vote. The problem with this projection is that Lombardo assumes the trajectory of the trend line will continue unabated through Election Day. My read of the latest national tracking polls, however, suggests that Romney’s “momentum” has dissipated, and that the race has settled into a rather stable equilibrium, with neither candidate showing an advantage. As evidence, consider the latest RCP composite poll, which shows the race essentially tied.
I have said all along that the state-level polls and the national polls will gradually converge. But in whose favor? In my next post, I’ll address evidence suggesting that Romney may benefit from an “enthusiasm” advantage among Republican voters. In the meantime, however, it is worth remembering that, once again, the “composite” political science forecast reveals that presidential elections are rather predictable affairs and that contrary to what some pundits have suggested, this election has – to date – contained few surprises.
So, who is really winning this race? As of today, it is political scientists.