Guide for watching presidential returns
State-specific polls indicate an approximate order of finish, from strongest Obama to strongest McCain. All of the states that have even a remote chance of going either way (i.e., not including safe states like Illinois) rank this way, in order of strength for Obama:
New Hampshire 4
New Mexico 5*
North Carolina 15*
West Virginia 5*
* denotes a state carried by Republican George W. Bush in 2004.
Bush won with a 16-electoral vote cushion over the 270 needed to win. Obama must win all of the states that John Kerry won, plus 16 electoral votes from Bush states (generally referred to as "red states" in the media). Obama's three strongest Bush states are Iowa, New Mexico and Nevada. Those states appear above the line above, marking the division between the competitive states that Obama needs to win and those he can afford to lose. Notably, Florida and Ohio, though big prizes, aren't needed for Obama to win, as long as he wins everything above the line.
When watching early election returns, if an eastern time-zone state below the line (like Virginia, Ohio or Florida) gets called for Obama, he probably wins, unless that gain is offset by a state above the line (like Pennsylvania) getting called for McCain. If Obama wins a well-below-the-line state like Indiana (the earliest state's polls to close), that will bode well for all of the states above Indiana in the list (including Missouri), and a rout is probably in progress. Conversely, if McCain wins a well-above-the-line state like Michigan, McCain is probably headed for a comfortable upset win.
If Obama wins all of the states above the line (along with New York, California, Maine, Vermont, Massachusetts, Connecticut, Rhode Island, New Jersey, Delaware, Maryland, Illinois, Washington, Oregon, Hawaii and the District of Columbia, all generally regarded as "safe" for Obama and hopeless for McCain), he wins with a vote to spare, regardless of what happens below the line. If Obama wins everything above the line and McCain wins everything below the line, but McCain picks off one electoral vote in Maine by winning the more conservative 2nd congressional district, we get an electoral college tie. That would send the contest to the House of Representatives, where Obama would be the sure winner. (The Senate would pick the vice-president, and they are certain to elect Biden.) In both cases, the newly elected House and Senate do the voting, and both are expected to be more Democratic than their current versions.
According to the latest state-specific polls, Obama leads in all of the above-the-line states, plus Colorado, Virginia, Ohio and Florida. But the polls have been wrong before.
I believe Obama will win even more red states, including Missouri, and that he will pick off an additional electoral vote in deep-red Nebraska by winning the Omaha-based 2nd congressional district. He will win the same way Bush did the past two years, with an excellent get-out-the-vote (GOTV) plan. The Obama campaign has apparently studied Bush's GOTV effort and replicated it, and that's what will propel Obama (and down-ballot Democratic candidates) to a strong victory tonight.