Addendum on Exit Polls
The findings presented in this analysis are derived primarily from New York Times exit-polls (data collected by Edison Research) from the 2008, 2010, 2012, 2014 and 2016 national elections. In anticipation of questions or objections from readers, allow me to briefly elaborate why I chose to rely on exit-polling for this analysis, and why readers should trust (and act on!) the findings.
Are exit-polls reliable?
The main purpose of exit-polling is to help media organizations 1) determine the winner of presidential elections as soon as possible and 2) gather additional information about who voted and why, for the sake of framing how particular electoral outcomes came about. While early results of exit-polls can be misleading—especially in the hands of irresponsible or sensationalizing bloggers and journalists–-finalized exit-polls tend to match closely the eventual outcomes of most races, making them reliable enough for our purposes.
Don’t exit-polls seem to systematically over-represent certain groups or districts?
Of course, exit-polls by their nature focus on Election Day turnout, and they cannot easily incorporate early-voting results. However, this is not a problem for us, as early-voting patterns have not proven terribly predictive or decisive in terms of how races ultimately turn out.
Additionally, because exit-polls primarily serve to determine the outcome of races as efficiently as possible, they tend to oversample highly competitive states and districts. This is actually a good thing for our purposes—relative to swing states and districts, the prevailing sentiment or demographic composition of partisan safe zones don’t matter much in determining the outcomes of elections. And it is the predicted outcomes of (future) elections that we are concerned about here–so the bias towards competitive territories is just as useful for us as it is for the exit-pollsters.
Finally, for various reasons exit-polls also tend to oversample Democrats and Democratic-leaning constituencies (by how much? See here). Again, for our purposes, this is not a problem. It means, if anything, our already-bleak narrative may be too generous to Democrats. It does not undercut our argument substantively—but instead renders our conclusions more urgent.
What about the margins of error?
It is true that the statistical margins of errors for exit-polls tend to be higher than other forms of polling, for reasons such as their strategic sampling bias. However, these concerns are largely theoretical (concerning the representativeness of the sample relative to the entire population). In practice, exit-polls do tend to reliably track with the outcomes of races, and that’s what matters.
More broadly, what is important to us is not so much the exact percentage of particular groups who lean one way or another in any particular contest, but instead, the longitudinal trend. To the extent that Edison Research’s methodology remains more-or-less consistent, we can be fairly confident in the directional trend while bracketing many of these other questions.
When we see clear patterns that persist over the course of the last three presidential races and the last three midterms elections—and most importantly–when the story told from the exit-polls matches and seems to well-explain the actual electoral outcomes we’ve been consistently observing over the past decade — as seems to be the case here — then we have pretty compelling reasons to trust the overall picture provided by the exit-polls about the direction various groups are travelling in (without over-investing in the specific share of the vote that specific parties won in specific years).
But how pronounced are the trends, really?
In evaluating longitudinal trends one could choose to look for patterns that persist across all general elections regardless of whether they were presidential years or not–-for instance lumping together 2006, 2008, 2010, 2012, 2014 and 2016 into one dataset. On this model, one would still see a clear downward trend, but it would seem kind of like a roller coaster.
Consider the Democrats’ share of the youth vote over the last six cycles: 61, 66, 58, 60, 55, 55. The story is still a significant net loss over the last decade, but it could look like the numbers have been rising and falling, and perhaps one might expect the next election will look better than the last. However, such optimism would be unwarranted:
In reality, midterms and presidential races have drastically different demographic constitutions. For instance, 18-29 year olds amounted to around 18-19 percent of all voters during presidential years, but between 11-13 percent during midterm elections. And the subset of young voters who turn out during midterms tend to have different sensibilities than the broader and more diverse group who participate in presidential elections.
For instance, if we separate the Democrats’ share of the youth vote by presidential years v. midterms, a different picture emerges. First, the trend is unanimously down: in presidential years, from 66 percent to 60 percent to 55 percent; in midterms from 61 percent to 58 percent to 55 percent. So there is little reason to expect, from the trend, that the next race would show an improvement.
However, one also sees that Democrats generally perform better with young people in presidential years than in midterms–benefiting from left-leaning irregular voters drawn in by the race for the White House. Therefore it is noteworthy that the Democrats ultimately ended at 55 percent vote share for both the last midterm and the last presidential election:
The Democrats’ decline among young voters has been far more dramatic among the last three presidential cycles vs. the last three midterms (down 11 percentage-points from 2008 in the former vs. 6 percentage-points since 2006 in the latter). This convergence is very bad news; it means Democrats may not be able to rely on a presidential-year bump from the youth in 2020.
Similar patterns emerge across demographic categories. When you do apples-to-apples comparisons of midterms and presidential cycles, the trend is dramatically and unrelentingly negative for the Democrats and, to a lesser extent, positive for the Republicans (and third-parties).
A note on strategy
Trump and the Republicans are now the default in American politics. They are in power, and will likely remain in power–even if they are widely disliked–unless and until the public sees a better alternative (as opposed to a possible lesser evil). After all, Trump was elected with record-high unfavorable ratings to begin with!
This essay highlights apparent trends in the way Americans are voting, and suggests that if these trends hold into the future, the outlook is not so great for Democrats. However, as the 2016 election cycle should have powerfully driven home, and as I underscored in the conclusion of the article itself, there are limits to polls and predictions.
Ultimately, Democrats have to choose what they’re going to believe. It seems clear what would be more pleasant to assume (i.e. the Emerging Democratic Majority is on track, Trump is an ill-fated anomaly, etc.)—however, this is perhaps not the most useful proposition to work from.
Consider a variation on Pascal’s Wager: if the analysis presented here is somehow overly-pessimistic (again, the typical bias from exit-polls suggests the opposite), but Democrats buy into the argument nonetheless—what would happen? They would urgently invest time and resources, reworking their platform, outreach and messaging in order to shore-up white voters while simultaneously energizing and mobilizing minorities. That is, the only possible outcomes are positive.
On the other hand, if the analysis presented here is correct, but Democrats fail to heed the warning—instead perhaps doubling-down on their current strategies—the results would be catastrophic for them.
That is, strategically speaking, there is really no reason not to take these findings seriously, and a number of reasons why Democrats should. But we all make our choices…
4/2/2018 UPDATE: In the New York Times, Tom Edsall has a great column both reinforcing the central claim of this article, and also highlighting a new study from Pew that shows just how much exit polls seem to oversample Democrat-friendly constituencies. In short: the situation for Democrats is likely to be dire if they cannot make significant inroads among whites, especially the white working class.