From last Friday, posted by Michael McDonald:
[About the] Gallup Editors' Election Poll Analysis that attempts to place Gallup's tracking poll horserace numbers in context with other polls. Two of three contributions emphasize the "stability" of the Gallup poll, which is not something I find particularly compelling since random sampling error could produce the appearance of stability when there is instability.
Perhaps the most interesting explanation has to do with the question sequencing and wording, where Frank Newport takes issue with the LA Times/Bloomberg poll for asking the direction of the country question before the ballot test.
Still, I'd like to see Gallup pull apart their poll more. What are the demographics and support among groups in comparison to other polls? I think a beginning towards the answer why Gallup is different will lie somewhere in there.
I also find it a little disingenuous to explain the differences between Gallup and the two double-digit Obama lead polls only. I'm willing to believe the truth lies somewhere in the averages, but this begs the question why the Gallup daily tracking is different from the single-digit Obama lead polls.