One day last week a Gallup poll had Bush up by 13 points -- and Democrats promptly broke into a panic and Republicans broke out the bubbly. But then a Pew poll called the race tied. What gives?
The Wall Street Journal (free link) tries to explain the volatility in polls on the front page today. The schizophrenic nature of the polls probably has more to do with polling techniques than an electorate veering sharply from one candidate to the next.
"Consider last week's Pew Research Center survey, which showed strikingly different research during two consecutive polling periods. In the portion of the survey conducted Sept. 8-10, Mr. Bush led Mr. Kerry 52%-40% among registered voters. In a separate portion conducted Sept. 11-14, Messrs. Kerry and Bush were tied at 46%. But there was one other key difference, too: Among voters sampled in the first portion, self-described Republicans outnumbered Democrats by two percentage points; in the second, Democrats outnumbered Republicans by four percentage points."
"Pew pollster Andrew Kohut described that difference as normal week-to-week drift -- because party allegiance is a fluctuating attitude -- that doesn't call his results into question. In fact, he says his surveys show the race is more volatile than other analysts have suggested. But the Bush campaign insists the partisan variation exaggerated the appearance of a trend toward Mr. Kerry." "Party allegiance 'does not change in seven days' by that much, says Mr. Steeper, the Bush pollster. He says Mr. Kohut should have 'weighted' his poll with a common assessment of partisanship for both samples; averaging the two would have shown the president with a steady lead of about six percentage points. Bush advisers were more pleased by a CBS-New York Times survey late last week showing the president leading Mr. Kerry by nine percentage points, 50% to 41%, up from seven points the previous week."
"Yet those CBS surveys were conducted the same way the Pew polls were -- without making any adjustment for the different number of Republicans and Democrats surveyed. And in the CBS polls, the number of Republicans surveyed rose sharply from the first week to the second. 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."
If all of this frustrates you, try not to take individual polls as gospel or just do as Jimmy Breslin does and ignore the "monstrous frauds" altogether.
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