Zogby's Internet poll from the same week had Obama up by 3.
Here's pollster's take on that shitty Zogby poll.
All pollsters, it seems, eventually find themselves with what Andy Kohut once referred to as "loopy" results. His comment was about the Gallup polls in the 2000 election, though in September 2004, Pew experienced such results itself, and of course several polls this campaign season have produced inexplicable or "wrong" numbers, as indicated by the subsequent primary election vote counts.
This time, it's Zogby's turn to confuse the masses. His latest Reuters/Zogby poll, based on a sample of 1,089 "likely voters" drawn from listed telephone numbers, conducted Aug. 14-16, 2008, shows McCain over Obama by 46% to 41%.
Two days earlier, Zogby reported substantially different results. His online poll (of self-selected people who want to be part of his Internet polling sample) of 3,339 "likely voters," conducted Aug. 12-14, showed Obama with a three-point lead, 43% to 40%.
Of course, there are reasons to discount both polls. Zogby has long been known for refusing to use sound methods in designing his samples. The use of only listed telephone numbers, and the self-selected samples of voters in his online surveys, are the two most salient problems. Still, his last pre-election polls often come close to the actual election results, and many news media outlets regularly publish his results.
Regardless of how loopy are Zogby's results, or his sampling methods, his polls contribute to what Kathy Frankovic, in her AAPOR presidential address in 1993, referred to as the "noise and clamor" of the polls. Thus, they're worth noting, if only in disbelief.
http://www.pollster.com/blogs/the_loopy_zogby_polls.php