The final voting precincts on the west coast won’t even begin to be tallied until early Wednesday morning, but the election could be decided much earlier than that.

Polls begin to close at 6:00 p.m. Eastern Time, and results will flood in not long thereafter. Whichever candidate reaches 270 electoral college votes wins the White House.

Crucially, Barack Obama won each of the swing states listed below in 2008.

7:00 p.m.: Virginia is the first battleground state to close its polls. Barack Obama has a slight lead in most recent polls, but the state is essentially a tossup. The president won the state in 2008 by 6.3% – but Mitt Romney has made it essential to his election strategy. If he wins Virginia, and its 13 electoral votes, it will confirm that the national race is as tight as everyone believed it to be. If Barack Obama wins, Mitt Romney’s chances of taking the White House become narrower.

Polls begin to close in North Carolina, as well. Barack Obama won the state by a narrow margin in 2008, though a strong rightward swing in the last four years means Romney has a large advantage.

7:30 p.m.: Polls close in Ohio – the most important swing state in the nation. This is a must-win for Mitt Romney. If he cannot take Ohio, with 18 electoral votes, he will have to win nearly every other swing state in the country. No Republican has ever won the presidency without Ohio. If Barack Obama loses Ohio, his chances of winning reelection become significantly smaller. Watch the Cincinnati metro area – which is perhaps the most important region of the state for determining the overall outcome. Barack Obama won Ohio by 5.4% in 2008.

It is important to note that Barack Obama is likely to take an early lead in Ohio as early voters are counted first. Polls show he leads among people who cast their ballots before Election Day.

The final voting precincts on the west coast won’t even begin to be tallied until early Wednesday morning, but the election could be decided much earlier than that

8:00 p.m.: Florida, New Hampshire and Pennsylvania close their polls.

Florida is another essential state for Mitt Romney, though it is less important to Obama’s strategy. With 29 electoral votes, Florida is the largest swing state in the country. Mitt Romney has a 1.5-point advantage, though both candidates have fought hard for it. However, don’t expect rapid results from the Sunshine state. Ballots in Florida are long and voting lines are expected to be even longer – meaning it could be hours before results are tabulated.

Pennsylvania, 20 electoral votes, is heavily leaning in Barack Obama’s favor, but Mitt Romney has fought hard to reduce the Democratic lead.

New Hampshire has just four electoral votes, but both candidates have visited multiple times. Barack Obama holds and edge in the polls, but Mitt Romney owns a house in the Granite State and was governor of neighboring Massachusetts.

9:00 p.m.: Wisconsin and Colorado polls close.

Colorado isn’t a big catch, with nine electoral votes, but it’s a major test of Barack Obama’s support among Hispanic voters. Both candidates have campaigned heavily here and Barack Obama has a narrow lead in recent polls.

A Mitt Romney win in Wisconsin would be hugely symbolic. With ten electoral votes, the state has not gone for a Republican since Ronald Reagan in 1984. However, Vice presidential candidate Paul Ryan hails from Wisconsin and the divisive Republican Gov Scott Walker recently survived a recall election. Polls show Barack Obama has a four-point lead in polls.

10:00 p.m.: Iowa and Nevada, the last of the swing states, close their polls.

Iowa has just six electoral votes, but it’s important to Barack Obama – it’s the state where his presidential campaign began in 2008. The president currently leads here, though it’s a traditionally white, working-class state with a largely rural electorate – all Mitt Romney’s strong points.

Nevada, also six electoral votes, is the westernmost swing state. Barack Obama leads here in polls, as well, though the economy has been badly battered by the housing crisis and unemployment is more than 11% – much higher than the rest of the nation.