What Is A “Likely Voter” Anyway?


Fresh off of our glimpse into the explosive turnout potential of the untapped conservative electorate, along comes a new report from The Pew Center which in its own way raises a similar question: Are “likely voter” models for the 2016 election cycle way off-base?

In other words, are we looking at another election in which mainstream polling completely misses the mark?

According to the Pew report, this polling “has missed the mark in several high-profile elections, drawing particular attention to the difficulties inherent in using surveys to predict election outcomes.”

“Election polls face a unique problem in survey research: They are asked to produce a model of a population that does not yet exist at the time the poll is conducted, the future electorate,” the report continued.

Indeed.  But that’s what survey work is all about – accurately modeling a voter universe that’s consistent with the electorate to come, not the electorate of years gone by.  To that end, Pew’s researchers surveyed verified voters from 2014 – uncovering a 51-45 percent advantage for Republicans (which mirrored the 2014 results, not surprisingly).

Those numbers different dramatically from Pew’s pre-election estimates, though – which found a 42-38 Democratic edge in September 2014.

“If we could have used the perfect knowledge of hindsight, however, and only selected those who would eventually be verified as having actually turned out to vote, that same September survey would have found that Republican candidates held a 3-point lead,” Pew’s researchers concluded.

In other words, an electoral universe modeled accurately at the time would have seen a seven-point swing.

So: Why the difference?  Did people simply change their minds?  Or did one party’s voters turn out in far greater (or fewer) numbers than expected?

“While changed minds contributed to some of the difference between the September poll result and the final outcome, this factor was less important than the turnout differential between Republicans and Democrats,” Pew researchers found.  “Fully 73 percent of pre-election registered voters who supported a Republican candidate in the pre-election survey ultimately turned out to vote on Election Day, based on verified vote from the voter file. By comparison, only 61 percent of registered voters who supported a Democratic candidate were verified to have voted.”

So how do pollsters take more accurate stock of the actual electorate – not the electorate they think will show up?

They don’t.  However, there are methods that will be tested in 2016 and beyond which could lead to better results.

“One solution is to use voter files as a sampling frame,” Pew researchers concluded.  “This is becoming more common as the quality of state voter files and the commercial databases built upon them has improved. These commercial files often include telephone numbers and additional political, demographic and lifestyle data about households. But they may have significant biases, with highly mobile and lower-income individuals underrepresented.”

Assuming such surveys were modeled to reflect these “underrepresented” demographics, though, such enhanced voter files could form the basis for more reliable sampling.

To view the Pew report in its entirety, CLICK HERE.