More pieces of the puzzle will start falling into place as polls close in the District of Columbia and 16 states, including battlegrounds Florida (29) and New Hampshire (four).
Democratic-leaning parts of Florida tend to be the last places to report, so be careful about jumping to a conclusion if Romney looks strong early on. Most of the polls in Florida close at 7 p.m. Eastern, so by 8 p.m. Eastern, when the last polls close, results will start to roll out quickly. But fully 4.5 percent of votes in Florida weren't counted on election night in 2008, so if things are tight, no one's going to be hasty about declaring a victor in the state. Especially after the 2000 fiasco in which the winner in Florida, and thus the presidency, wasn't determined for more than a month. If you want to get really granular, Hillsborough County, home to Tampa, is widely considered a bellwether for the state.
Tiny New Hampshire is another competitive state to watch closely.
Also keep watch on Pennsylvania for any signs of a Romney surprise. The state has long been considered safe for Obama, but Republicans started running ads there in the final week of the campaign and the GOP ticket was campaigning there Sunday. No Republican presidential candidate has carried the state in nearly a quarter century.
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