Divergent Opinion Polls Reflect New Challenges
Divergent Opinion Polls Reflect New Challenges to Tracking Vote (John Harwood, WSJ)
Widely divergent poll results in recent days underscore a paradox of the 2004 presidential race: Despite all the surveys, it may be the toughest election in memory for anyone to track.
Opinion polls themselves had been getting harder to conduct long before the matchup between President George W. Bush and his Democratic rival, Massachusetts Sen. John Kerry. The reasons range from growing reluctance to participate in surveys to increasing reliance on cellphones rather than the land lines pollsters have long used to ensure demographic and geographic balance in surveys. But this year’s bitter presidential contest has heaped on new challenges. They include an exceptionally close race and a polarized electorate that magnifies the consequence of different polling methods. In addition, unprecedented voter-mobilization drives by both parties make it especially tough for pollsters to say which voters probably will show up on Election Day. “It makes it harder” to forecast the likely electorate, says Fred Steeper, a longtime pollster for Mr. Bush. In the six weeks to Election Day on Nov. 2, he adds, disparate polls may reflect sampling error and methodological differences more often than shifting opinion. “My advice to the consumer is … the day-to-day reports of polling will exaggerate the changes in this race.”
Adding to the confusion is the way poll reports themselves become weapons in the campaign. The Bush campaign swiftly touts favorable surveys and seeks to discredit those showing Mr. Kerry drawing closer. The approach plays on the so-called bandwagon effects that energize supporters of a surging candidate and dispirit those of a lagging one.
Underlying those conflicting arguments aren’t just different political calculations but also differences in polling philosophy and techniques. Consider last week’s Pew Research Center survey, which showed strikingly different research during two consecutive polling periods.
Last week’s CBS sample, in a mirror image of Pew’s, contained four percentage points more Republicans than Democrats. Because this polarized contest has left roughly nine in 10 adherents of each party supporting its nominee, such variation in the number of Republicans and Democrats surveyed has an unusually large impact on polling outcomes. In a close race, in fact, that can make the difference between an apparent dead heat and a solid lead for one candidate. If the CBS and Pew surveys are adjusted to reflect comparable numbers of Republicans and Democrats, their results would have been virtually identical.
Indeed that’s precisely what liberal polling analyst Ruy Teixeira did on his Web log, called Emerging Democratic Majority. As the New York Times report of the poll carried the headline “Bush Opens Lead,” Mr. Teixeira’s blog declared, “CBS News/New York Times poll has it close to even.”
Mr. Teixeira argues that the Democratic edge Mr. Kohut found is realistic, since exit polls from the 1996 and 2000 campaigns indicated that in both cases four percentage points more Democrats than Republicans showed up to vote. Slightly more self-described Democrats than Republicans voted in the 1984, 1988 and 1992 elections as well.
Just who will turn out represents one of the biggest quandaries facing pollsters. About 105 million ballots were cast in 2000, and all sides agree more Americans will vote this time. Bush strategist Karl Rove predicts a total of around 110 million; Democrats estimate an even larger turnout, with some projections as high as 120 million. Close to election time, pollsters like to report results among those considered most likely to vote on the theory that those results will align most closely with the final outcome. But weeks away from Election Day that’s especially difficult to do, since many of the campaign’s mobilization activities occur immediately before the election. “I don’t know how you factor that into your polling,” Mr. Steeper says. Adds Democratic pollster Peter Hart, a veteran of presidential politics who helps conduct the Journal/NBC survey: “This is art. This isn’t science. Nobody knows.”
The Journal/NBC survey uses a single question to identify likely voters. It asks respondents to assess their interest in the election on a 10-point scale with 10 as the highest; those responding 9 or 10 are called likely voters. The Gallup Poll, which provides surveys for CNN and USA Today, among others, assesses likelihood of voting in a different way that has raised the ire of the Kerry campaign. Gallup asks a series of questions first devised decades ago that assigns voting probability to each respondent; it then uses their answers and an overall estimate of voter turnout to identify the likely electorate.
“We’re open to any scientific evidence that would point to our modifying our likely-voter model,” responds Frank Newport, editor-in-chief of the Gallup Poll. Mr. Newport says so far he hasn’t seen any.
All the major polling firms are pretty sophisticated in their techniques. If they weren’t, they’d lose credibility in a very competitive industry and go under. The RealClear Politics method of averaging all the polls is likely the best guestimate of where the electorate is. I’m much more comfortable with professional pollsters with honest, if minor, disagreements as to screening methodology than I am with intentional manipulation of the data by those such as Teixeira who have an obvious agenda.