The Economist/YouGov just published a poll that was conducted in mid-January. Here’s a data array that’s of some interest for this question – namely, “If an election for president was going to be held now, would you vote for….” Here are the results:
- The Democratic Party candidate: 39%
- The Republican Party candidate: 46%
- Other: 2%
- Not sure: 12%
- I would not vote: 2%
If we toss out folks for aren’t going to vote and folks who are planning to vote for a 3rd party candidate, then we have Republicans getting 47.9% (=46/96) of the vote and Democrats getting 40.6% (39/96) of the vote, with the remaining 12.5% (=12/96) in play. In order to win, Democrats would have to capture the remaining 5/6 of the undecided votes. All other things being equal, that’s highly unlikely. Very few demographic groups regularly go that strongly for either party by this large a margin, and given that the undecided voters are, well, undecided after all, they are likely to break fairly evenly for either party. Getting 60% of the remaining 12% would be quite a victory; getting almost 85% would be a miracle. This is bad news for the Democrats.
How good is the polling data? Glad you asked. This poll has reasonably good credentials, though some think that it tends to favor Republicans and typically Republican causes. Moreover, the data it presents is a month old, and this olde world moves mighty fast these days. But I should clarify that though the survey as a whole aims to get at the attitudes of adult Americans, the question about who one would vote for was limited to people who self-identified as registered voters. Nevertheless, it’s worth noting that 98% of these registered voters claim that will vote this fall. Fat Chance! In fact, 85% is a more realistic number. In 2012, the rate was a tad higher: 86.3% (=126,144,000/146,311,000). More generally, voter turnout in U.S. presidential elections has oscillated between 45% and 65% since 1908, and it hasn’t been over 60% since 1968.
If those registered voters planning to vote for the Democratic Party candidate turn out at just over 90%, while those planning to vote for the Republican Party candidate turn out at a rate of just under 80%, then the number of voters for each party’s candidates would be very close to equal, so it would come down to who is able to get the largest share of those who are both currently undecided and likely to vote in the fall.
How likely is that to happen? One’s initial reaction might be: Not Bloody Likely. After all, “Republicans are more likely than Democrats to turn out”. But the question isn’t, “Are you more/less likely to turnout, given that you’re a Republican.” The question is, “Are you more/less likely to turn out, given that you’ve said you plan on voting for the Republican candidate.” Only 27% of the respondents self-identified as a Republican, fewer than those who self-identified as a Democrat. That suggests that many of those who intend to vote for Republican candidate (or, more precisely, would do so if the vote were today) are among the 29% who self-identify as independents or the 10% who choose “Not Sure” as an answer.
So if – and it’s a big if – this poll tells us something useful about the 2016 election it might be that it could come down to whether self-identified independents and other unaffiliated registered voters show up to vote. And how, I ask you, do we estimate the probability of that?
https://d25d2506sfb94s.cloudfront.net/cumulus_uploads/document/ctucuikdsj/econToplines.pdf – Question 30
https://d25d2506sfb94s.cloudfront.net/cumulus_uploads/document/ctucuikdsj/econToplines.pdf – Question 76