Presidential election: How soon will someone win so we can go to sleep?

When will someone win the presidential election so we can all go to sleep? That’s the question that lots of people asked us while we waited in line to vote Tuesday morning. We can’t answer that for sure, but it’s possible to pinpoint when the US public might begin to get hints as to how the 2012 vote will play out. Here’s a quick rundown so you can plan when to walk the dog/check kids’ homework/make a burrito run to Chipotle.

First, a technical note – some states have split poll closings, with voting in different counties ending at different times. We’re ignoring that for the sake of simplicity.

That said, the first point at which something exciting can occur might be 7 p.m. That’s when the polls in six Eastern states close, with Virginia being the most important. Formerly solid red, Virginia has become much more of a swing state due to the fast growth of the D.C. suburbs in the northern part of the state. President Obama won there in 2008 by more than eight percentage points, but averages of major polls have the Old Dominion as a tossup in 2012.

Mitt Romney badly needs Virginia’s 13 electoral votes if he’s to put together the 270 he needs for victory. That means that if the networks call it quickly for Mr. Obama, it might be time to start plumping the bedroom pillows.

At 7:30 p.m., the polls close in Ohio. Do we even have to describe how important Ohio is to the calculations of both campaigns? It’s the state Obama has visited the most during the campaign, though there’s no truth to the rumor he’s had his middle name changed to “Columbus." If Ohio is called quickly for one candidate or the other, it could be a great portent of victory; that’s unlikely to happen, though, given the closeness of state polls and the large number of provisional ballots that Ohio election officials expect to wade through.

North Carolina polls close at 7:30, too. That’s a state that Mr. Romney should win, perhaps easily.

Eight o'clock is when things will really start to happen. If Dan Rather were still a network anchor, this is the time when he’d produce a colorful saying, such as “hang on to your armadillo and don’t forget the cheese dip, the hat’s really at the cleaners now!” Fifteen states ending voting at 8 EST, including Florida, New Hampshire, and Pennsylvania.

Again, it’s unlikely these states produce clear winners right off. But Romney has to have Florida and its 29 electoral votes. If Obama wins there, it’s time for some bedtime reading. Conversely, Pennsylvania and its 20 electoral votes is, or was, supposed to be safe Democratic territory. Romney is now contesting that, and he had a big closing rally in Pittsburgh. If this doesn’t fall fairly quickly into the Democratic category, they’ll start to sweat at Obama headquarters in Chicago.

For Romney, a win in Pennsylvania could counteract a loss in Ohio, keeping him in the game as the closing times sweep west across the US.

Oh, you want to know about New Hampshire? It has only four electoral votes, but it’s a true swing state, in the sense that it’s full of voters who are actually persuadable. It’s the only state that George W. Bush won in 2000 but lost in 2004. In 2012, both candidates have spent precious time there in the waning days of the campaign. There’s little early voting here, so New Hampshire could show which way the late momentum has been trending.

At 9 p.m. EST, 14 more states shut their polls. Among them are Colorado, the closest swing state of all, and Wisconsin, where Obama leads but Romney has made a strong push. If either candidate wins both Colorado and Wisconsin, he's almost certain to win the election.

Michigan closes at 9 p.m., as well. The Wolverine State should be solidly blue, despite Romney’s family history in the state. If it’s even close there, it could portend a long night for Democrats.

At 10 p.m., Iowa and Nevada end voting. Most Nevadans actually vote early or absentee, so the outcome should get called fairly quickly. Obama has a comfortable, if not large, lead in Nevada, according to the polls; if he doesn’t win there, it’s not fatal to his chances, but it wouldn’t be good. It might be an indication that the Hispanic vote isn’t turning out for Democrats as much as they’d hoped.

Iowa is razor close. Obama ended his campaign there, saying it was because he wanted to finish in the state where his presidential hopes began in 2008. He could lose Iowa’s six votes and still find ways to reach 270. For his part, Romney needs the state badly.

After that, the states still voting will be mostly nonbattlegrounds. At 11 p.m. EST, polls in five West Coast states close, including California, biggest prize of all with 55 electoral votes. Alaska ends voting at 1 a.m., bringing an end to an expensive, clamorous, and close 2012 presidential campaign.