Senator Barack H. Obama has a huge lead. No, Senator John S. McCain, III is closing the gap. The next poll shows Obama running away with the election. With McCain it is a two-point race. No, Obama is seven points ahead. Confused? We all ought to be.
This election season there are polls galore - four times the number in 2000, close to three times the number in 2004. When we see on the same day one poll reporting that Senator Obama is 16 points ahead of his rival, Senator McCain, and another poll stating that there is a one-point differential, essentially a statistical tie, we can't figure out what is transpiring.
Let me attempt to explain. To obtain an accurate or reasonably accurate sampling of American voter sentiment we must know precisely the composition of the American electorate. One poll or survey - whatever it is called - may have included all respondents, registered to vote or not. Another on the same day may have included only folks registered to vote. Yet another on that day may be based upon a group of respondents evaluated most likely to vote. Hence, we could have three very differing results.
When I was consulting with campaigns we usually took a survey at the beginning of the race to determine where the candidate stood in terms of name recognition, positives, negatives, match-up with the likely opposition, so on. Around the middle of the campaign we would survey the same folks to learn if we had made progress in swinging voters in our direction and to gain information as to how our positives and negatives stood. We then always surveyed a week out so we would know what we needed to do to close the gap and win the election.
In addition - but very important, the geography of a Presidential poll is very significant. Everybody knows the District of Columbia and Massachusetts will vote overwhelmingly Democratic, Alaska and several small Mountain and North Central States will vote Republican (if not necessarily as overwhelmingly). Thus, polling of swing States is much more meaningful.
Cliché that it is, it's worth repeating: There is only one poll which counts - election day. In those States which have early voting Democrats and Republicans appear to be neck and neck. We well may be in for a long night on November 4.