I ran across this comment to a Charlie Cook column in the National Journal Online - which is spot on from a real sharp guy:
As a professional poller (I gave up political polling 20 years ago, and now mostly poll for litigation), I find Charlie Cook's comments about the change in the race surprising. I think the key is to understand that there are effectively three sets of pollers operating today, and they are getting three sets of different results. The reason for the differences is almost certainly a combination of how they define likely voters, and how hard they push the undecided to get answers. Thus category 1 which gets the most Republican vote (I'm not saying they are biased in that direction just that their results come out that way) includes, for instance, all those who use Gallup methods. Category 2 is those who have never seen any edge for either candidate, the best exemplars being ABC and Rasmussen. Group 3 is those who have consistently shown Kerry much further ahead, with Zogby being the best example.
Consider polls around the end of July, beginning of August - Gallup had Bush up 4, An average of two ABC polls had a dead heat (Rasmussen's average result was also roughly even), and Zogby had Kerry up 5.
Now consider results at the end of August - Gallup had Bush up 3, ABC had a tie (Rasmussen had Bush up 1) and Zogby/Williams had Kerry up somewhat over 4.
In other words there has basically been no change in the results from most of the specific pollers (the theory holds for among others NPR, Pew, and the Economist). What changes over time is which pollers have produced results - anytime a new poll comes out from the L.A. Times instead of CBS/New York Times Bush looks better and vice versa. In other words, the changes aren't in the race, they are in which pollers poll at specific points in time, and which ones get publicity.
Posted by: Mike Rappeport at August 31, 2004 12:11
Poll Analysis
Get that? NOTHING has changed. Swifties have done nothing. That is the race is STILL Kerry's to lose. All of this panic and BS is a creation of a Media fallacy - that there has ACTUALLY been poll movement.
In other words, Bush is toast. Kerry has had the worst possible 3 weeks he could have and NOTHING has changed! So, let's just prepare our laugh at the idiot Media as they try to explain away Kerry's soon to be spotted "resurgence."
BTW, how can I vouch for this guy? I know him. I've deposed him. In litigation surveys, he is one of the best in the business. And let me tell you, litigation surveys are ten times as rigorous as political polling.
This guy knows much more about it than Charlie Cook.