With all the usual caveats on this being only one poll, USA Today/Gallup just published the first poll with McCain in the lead since May 1st. Back then, McCain only lead by one.
McCain 49 (45)
Obama 45 (50)
That’s an unlikely 9 point shift from “late June.” The most interesting factor seems to be the likely voter screen. McCain leads among Likely Voters 49-45, but “Among registered voters, McCain still trails Obama, but by less. He is behind by 3 percentage points in the new poll (47%-44%) vs. a 6-point disadvantage (48%-42%) in late June.”
Bottom line, I don’t think if the election were today McCain would win by 4. But I also don’t think Obama would win by 8. I think this is why averaging polls helps soften the quick deviations and thus using RCP’s average is quite helpful. Currently, they have Obama +3.2%. That’s about President Bush’s margin in 2004; in other words, it’s still very close.