Here's another weekly installment of my simulations of the general election results using polling data from Votemaster Andrew Tanenbaum's www.electoral-vote.com.

The usual caveats apply: it's still June, polling is unreliable, and many of the polls are quite old now anyhow. But to paraphrase our former secretary of defense, you analyze the data you have, not the data you'd like to have.

Again I'm running 10,000 trials of the election using two different margins of error:
4% Margin of Error
Obama wins 99.87%, averages 327 EV
McCain wins 0.10%, averages 211 EV
Electoral tie 0.03%

12.8% Margin of Error:
Obama wins 94.4%, averages 314.2 EV
McCain wins 5.3%, averages 223.8 EV
Electoral tie 0.3%

The 4% margin of error that reflects the statistical margin of
error of most polls. 12.8% comes from a
linear regression of polling errors in 2004 using days until the
election as the independent variable. The former captures only sampling
error for polls, and does not allow for movement of opinion in the
electorate itself. The latter tries to allow for such movement by using
a wider margin of error, although because I'm still treating each
state's as an entirely independent random event, this doesn't reflect
the likelihood that improving your vote in one state also improves it
in others. So both of these simulations overstate the likelihood of
Obama actually winning right now.

Obama is now trailing by just 4 in Alaska, he's closed to a single-digit deficit in Arkansas, and he's taken a 1 point lead in Virginia. Two recent New Hampshire polls both give Obama double-digit leads, he's now just 2 or 3 back in Nevada, and as Josh noted earlier this week, he trails by only 12 in Kentucky despite his lopsided primary loss. Not all the movement is in his favor: Minnesota has tightened to a 1 point race (this may be in part pollster differences: Survey USA's last previous poll had Obama up just 5, but in between two Rasmussen polls gave Obama double-digit leads); Obama is up just 2 in Colorado; and McCain has closed to 4 back in Iowa. Bob Barr gets enough support in Georgia that Obama was just down 1 in the last poll.

The huge change here is, of course, Florida. Rasmussen had given McCain regular double-digit leads earlier, and their latest poll still says he's up by 8. Quinnipiac had smaller McCain leads before of between 2 and 9 points, but now they show Obama up 4. ARG's first Florida poll, released this week, has Obama ahead by 5. So while Florida seemed perhaps a likely safe McCain state a week ago, it's now quite clearly in play, which greatly changes things. It's hard to envision McCain winning without Florida, so that's the biggest cause of his dropoff in my simulations.

Personally, I think expecting a 95% probability of Obama winning greatly overstates things, but this exercise does capture that he's showing increasing strength in more of the country. It validates the 50-state strategy: the more of the country you put in play, the more ways you have to win. Obama already was able to win without Florida and Ohio, but it would have been quite hard. With states like Virginia, Colorado, Nevada, and North Carolina potentially in play, he has much room to compensate if he's weaker in some areas.

This may not have been the best of weeks for the fourth amendment, but it's been a good one for Obama's polling numbers.