Let's just start things off with a nice, big chart:
You
should notice a couple of new features. Firstly, I am now listing the
national polls that have come out since the last update -- today there
are a ton of them -- just so that we can be more fully transparent.
Also, we now have a way to indicate tracking polls: they are designated
with a slash. So, for instance, a "3000/3" (as for the Rasmussen
Tracker) means that the poll included a rolling sample of 3,000 voters
conducted over a 3-day window.
Obviously,
there are a lot of great numbers for Obama today. Essentially all of
the CNN polls look good for him, as do the other couple of Florida
polls. Rasmussen has him maintaining his lead in North Carolina, and
PPP has him way ahead in Michigan -- enough, apparently, that MCcain
has now given up on winning the state (more on this when I get a moment).
There
are also a handful of good numbers for McCain -- Mason-Dixon in
Virginia, and the New Mexico polls show Obama stalling a bit, though
still comfortably ahead. But clearly, it's been a big Obama day, and
the McCain campaign now seems to be aware that their electoral map is
falling apart.
Somewhat counterintuitively, Obama's national win
percentage did not increase; in fact, it went down just a tick from
yesterday. This is principally because the model had already "priced
in" a lot of these sorts of results. It expected, for instance, that
when CNN again polled a state like Florida, it was going to show a very
nice result for Obama, since CNN had been relatively favorable to Obama
in Florida before. Also, when there is such a high volume of data to
process, the regression models that underlie the model can be
significantly recalibrated, which can shift things by a point or so
here and there.
Let's not get bogged down in the technicalities,
however. Clearly, the McCain campaign is now on the defensive, and
needs to knock a couple of points off Obama's numbers across the board
before it starts to reestablish some sort of winning electoral map.
Tonight's debate could be a step in the right direction -- or, if
things go badly for Sarah Palin, a near-fatal blow.
--Nate Silver