November 4, at 9pm Eastern, 6pm Pacific. That's the time I calculate that the news networks should be calling the Presidential race for Obama. Polls will close at that time in 12 states (give or take a few areas within those states), and the networks will call each state for one candidate or the other, unless the vote is very close in any given state.
Disclaimer: I apologize if I've miscalculated in some way. I'm just trying to figure out how many hours we have left till celebration time. I especially apologize to West Virginians, Georgians, Eastern Nebraskans and everyone else working hard to turn red states blue. I know we can take some places I've marked as red.
Here's a detailed graphic of poll closing times.
Here's an approximation of what the electoral map will look like at 9pm Eastern, 6pm Pacific:
Obama 286, McCain 145 (270 to win)
The point I'd like to make is that an early election night victory for Obama may cause big problems for Republicans in the West (as if they didn't have enough troubles already).
A famous story tells that in 1980, when the networks awarded the Presidency to Ronald Reagan early in the evening, disgusted Democrats in Western states actually got out of line to vote and went home. This of course had a devastating effect on Democrats in races down the ballot. According to the 1988 NYT article linked above:
Several Democratic legislators, including the late Senator Frank Church of Idaho and the late Representative Al Ullman of Oregon, blamed Mr. Carter's early concession for their losses.
Republicans may experience the same phenomenon this year if Obama is declared the next President while the polls are still open in eleven western states. I, for one, will not be sorry for them.
Of course, unlike Carter, Mr. McCain may not choose to give his concession speech (which will be out on the lawn?!) until the middle of the night. But in 2008, when CNN says it's over, every one will know it's over, no matter what McCain does before his imminent retirement from public life.