Thanks to everyone who has written in, I appreciate being able to make a difference. But I still hear a lot of worry and doubt from republicans about whether McCain can really win the election. This article is one reminder about why this race is still a very close race, and why you not only must not give up, but why you can make a big difference in this home stretch.
I wrote Friday about the fact that in seven of the last eighteen presidential elections – 38.9% – the polls were wrong by a big margin on the race, and so even a big lead for one candidate does not guarantee diddly. I have discussed the principles of statistics to show why the present polls have a critical flaw somewhere in their methodology, since the results are not in line with the confidence criteria. But there’s another way to take apart a poll to see whether it is useful as a barometer for opinion.
The widest lead enjoyed by Obama in the major polls Friday, was the Gallup Daily Tracking Poll. Gallup has been in the business longer than anyone else still doing polls, so it appears reasonable to consider Gallup’s reports to have solid credibility. The problem, of course, begins with the fact that so many other polls show the race being closer. But let’s look at that Gallup poll to see if we can learn from it.
Friday’s tracking poll had Obama up by ten points. But that lead is actually the result of two separate tracks, one for Obama and one for McCain. 51 to 41, so they say.
OK, that’s their starting number, the one they put in the headline. What drives those numbers, I wonder? I always want to see the internals, but Gallup has been getting sneaky, they release that data later, generally a week afterwards. The most recent detailed support by party I have is from the week ending October 5, when Gallup had Obama leading 50-42. I also note for reference that Gallup showed Obama leading 50-42 on September 28, 48-44 on September 21, and McCain leading 47-45 on September 14. The party affiliation for those dates should help us see where the changes came from.
Let’s start with Gallup’s base support for the race, conservative republicans for McCain and liberal democrats for Obama. Here’s how that looked:
Sep 14: McCain 95%, Obama 94%
Sep 21: McCain 93%, Obama 95%
Sep 28: McCain 93%, Obama 95%
Oct 05: McCain 94%, Obama 95%
Pretty comparable, noting to show a reason for changes. Next up, cross-party support, conservative democrats for McCain, liberal/moderate republicans for Obama:
Sep 14: McCain 17%, Obama 16%
Sep 21: McCain 19%, Obama 15%
Sep 28: McCain 19%, Obama 15%
Oct 05: McCain 16%, Obama 19%
Well, Obama got a boost going into October, but this is a pretty small group, hard to see it swinging the overall vote by the way we’ve seen. That leaves the independents:
Sep 14: McCain 38%, Obama 24%
Sep 21: McCain 31%, Obama 22%
Sep 28: McCain 31%, Obama 22%
Oct 05: McCain 32%, Obama 23%
McCain has a good advantage here, so that cannot explain the deficit. As I explained before, the only way this can be happening, is that Gallup has weighted the democrats more heavily, assuming that they will be a greater portion of the voter population this year than in past elections.
– continued –
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