Tag: Political Polling


Weighty matters: confirmation bias and polling

A little less than ten years ago, the firm I worked for was commissioned to poll the Georgia general election. We included a ballot question for the Governor’s race, which I often like to include because it gives us a benchmark by which to compare our surveys against other publicly-released surveys. At the time every single poll that was published had Barnes winning:

In the final poll taken before the 2002 Georgia gubernatorial election, incumbent Roy Barnes held an eleven point lead over his Republican challenger, Sonny Perdue (Salzer 2002a). This was hardly surprising. Barnes, a first- term Democrat, had led in every public poll taken since the campaign began (Dart 2002), and Perdue never edged closer than seven percentage points until election day (Beiler 2003).

When our sample came back showing Perdue with a narrow victory, I simply didn’t believe it. I was scared to give the client a survey analysis that included something that was so clearly wrong because it would lead the client to doubt everything else in the poll. I actually asked management to authorize a re-sample, and when it came back still showing a Perdue victory, I sheepishly gave the results to our clients.

We now know what happened several days later.

Once Georgians had their say on November 5, however, Barnes’ defeat was more than stunning—it was historic. Not only had Perdue overcome what seemed to be insurmountable polling and fundraising disadvantages, his election broke a Democratic stranglehold on the Georgia governorship that had kept the GOP out since Reconstruction. For a Republican running for governor in Georgia, Perdue won an unprecedented share of the vote among rural whites, an indication of a continuing realignment in favor of the GOP (Wyman 2002, 3). In winning 51 percent of the vote, Perdue had broad support, carrying 118 of the state’s 159 counties.

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