The impact of Wednesday night's debate is hard to gauge given the tracking polls that are out so far. McCain moved up in the Research 2000 and Battleground polls. Obama moved up in Diageo/Hotline and IBD/TIPP. Zogby, Gallup and Rasmussen were essentially unchanged.
The best number for McCain comes from the daily sample in the Research 2000 tracking poll, which showed McCain down by just 6 points in interviewing conducted yesterday. I say 'just' because the R2K poll has generally had pretty good numbers for Obama and it's been a couple of weeks since McCain was as close as 6 points. Small sample size caveats apply.
On the other hand, it appears to me from analyzing the cross-tabs in the Rasmussen debate poll, that Obama had quite a strong day in Rasmussen's tracking yesterday, winning the daily sample by 9-10 points. If I'm right, then Obama's number in the Rasmussen poll is liable to improve over the weekend.
In other news, the Supreme Court overrulled the Sixth Circuit Court of Appeals and determined that Ohio need not verify the names of newly-registered voters against Social Security databases. (Actually, this is not quite what they ruled; they ruled that the Ohio Republicans did not have the standing to be a plaintiff in the case). I've been resisting commenting on this stuff because the impact is hard to assess; off the cuff, I'd guess that it makes a smaller rather than larger difference, probably less than one full point.
And is Colin Powell about to endorse Obama? The Obama campaign certainly isn't doing anything to tamp down the speculation. For our part, we've been hearing rumors of a Powell endorsement for a long time now -- specifically, we'd heard that Powell might endorse Obama immediately following the Republican convention. But it would be typical of the very deliberate Obama campaign to hold an endorsement until now, when it can be used to run further time off McCain's clock. Mostly, endorsements serve to win news cycles rather than win over voters, although Powell is probably the biggest 'get' there is in this election (unless perhaps Ross Perot decided to endorse).