It's Tuesday, November 4th, 2008, Election Day in America. The last
polls have straggled in, and show little sign of mercy for John McCain.
Barack Obama appears poised for a decisive electoral victory.
Our
model projects that Obama will win all states won by John Kerry in
2004, in addition to Iowa, New Mexico, Colorado, Virginia, Nevada,
Florida and North Carolina, while narrowly losing Missouri and Indiana.
These states total 353 electoral votes. Our official projection, which
looks at these outcomes probabilistically -- for instance, assigns
North Carolina's 15 electoral votes to Obama 59 percent of the time --
comes up with an incrementally more conservative projection of 348.6
electoral votes.
We
also project Obama to win the popular vote by 6.1 points; his lead is
slightly larger than that in the polls now, but our model accounts for
the fact that candidates with large leads in the polls typically
underperform their numbers by a small margin on Election Day.
This
race appears to have stabilized as of about the time of the second
debate in Nashville, Tennessee on October 8th. Since that time, Obama
has maintained a national lead of between 6 and 8 points, with little
discernible momentum for either candidate. Just as noteworthy is the
fact that the number of undecided voters is now very small,
representing not much more than 2-3 percent of the electorate.
Undecided voters who committed over the past several weeks appear to
have broken roughly equally between the two candidates.
Our
model forecasts a small third-party vote of between 1 and 2 points
total; it is not likely to be a decisive factor in this election except
perhaps in Montana, where Ron Paul is on the ballot and may garner 4-5
percent of the vote.
Any forecasting system is only as good as
its inputs, and so if the polls are systematically wrong, our
projection is subject to error as well. Nevertheless, even as we
account for other cycles in which the polling numbers materially missed
the national popular vote margin (such as in 1980), a McCain win
appears highly unlikely. It is also possible, of course, that the polls
are shy in Obama's direction rather than McCain's, in which case a
double-digit win is possible.
Nor does McCain appear to have
much chance of winning the Electoral College while losing the popular
vote; in fact, our model thinks that Obama is slightly more likely to
do so. McCain diverted many of his resources to Pennsylvania, a state
where he narrowed Obama's margins somewhat, but which our model
concludes that Obama is now virtually certain to win. This may have
allowed Obama to consolidate his margins in other battleground states,
particularly Western states like Colorado and Nevada to which McCain
has devoted little recent attention.
Thank you for placing your
trust in FiveThirtyEight.com and the New Republic over the course of the past several
months. I hope that you will join me on the web tonight as well as on HDNet, where I'll be providing election coverage to Dan Rather's
team.
--Nate Silver