As results start pouring in tonight, a handful of states will tell you where this election is going. It takes 270 electoral votes to win. Here's what to watch (all times Eastern Standard).
Polls close at 7 p.m.
Virginia: Sen. John McCain spent precious last-minute time in Newport News, as sure a sign as any that his campaign believes polls that show Sen. Barack Obama leading. If this Republican redoubt flips from red to blue for the first time since 1964, it's a sign that McCain is in for a long night.
Georgia: Heavy turnout among African-Americans could put this rock-solid Republican state in play. McCain leads in polls, but it's still a tossup. If McCain wins, he's meeting expectations; if Obama wins, this election could be over early.
Indiana: McCain is scarcely ahead in a state that has a perfect GOP voting record since 1964. Obama made inroads as a favorite son of neighboring Illinois and a win here would be a startling turn against the GOP.
Polls close at 7:30 p.m.
Ohio: Along with Florida and Pennsylvania, it's one of three traditional battleground states. Polls show Obama leading, but McCain is running hard and Ohio is not quite as predisposed to Democrats as Pennsylvania.
Polls close at 8 p.m.
Florida: Most of the state's polls close at 7 p.m., but the Panhandle time zones are an hour later. It's quite simple: The electoral math doesn't work for McCain without having Florida in his column. If Obama manages to hold on to his lead in the polls (which has been slipping) and captures the state, McCain would have to score an unlikely set of upsets to recover.
Pennsylvania: This rich prize has tilted toward Democrats in recent elections and favors Obama strongly in the polls. McCain has not given up, though, and an upset win here could signal that McCain is drawing blue-collar voters who are important in other key states like Missouri.
Missouri: McCain is leading slightly in this swing state that has voted with the winner every time since 1964. It has been a historic bellwether, but the new map that has so many traditionally Republican states in play means a victory here may be less important than it has been.
Polls close at 8:30 p.m.
North Carolina: Polls show a tie, but implications of an Obama victory here would be significant. Like Virginia, this Southern state is one McCain was expected to win.
Polls close at 9 p.m.
Colorado: Democrats held their convention in Denver to capitalize on a trend that had been showing up in recent elections. Now Obama is favored to win the state that has gone with a Democrat only one other time since 1964. If so, it could be the first sign that the GOP hold on the West is cracking.
Montana: Not many votes here, but this state shares Colorado's history of choosing Republicans (except Bill Clinton in 1992). President Bush carried this state by huge margins both times.
Arizona: McCain leads in his home state but not by much. It's considered a tossup. If Obama snatches this one, McCain would be in a bad, bad spot in terms of electoral votes and embarrassed on top of it.
Polls close at 10 p.m.
Nevada: In the last battleground state before the solidly Democratic West Coast, Obama leads by an average of 6 points. This state has mostly been Republican, but it did support Clinton both times.