US election results: Swing states decide Obama-Romney's fate

Here's a look at the swing states that hold the key to the now-suddenly neck-and-neck US Presidential Election 2012 between President Barack Obama and his Republican challenger Mitt Romney.

Nevada, where two-thirds of the electorate votes early, has been moving Obama's direction in recent weeks, powered by strength in huge labour and Hispanic voting blocs. A Romney incursion there would really mean something.

Colorado, where almost 80 percent of voters cast early ballots, could be a straggler because it's so close. Historically, as much as 10 percent of the state's vote doesn't get counted on election night, and those ballots could be decisive in a close race.

Young professionals and Hispanic voters were central to Obama's victory there in 2008, but the sluggish economy has hurt his standing.

Iowa's been leaning toward Obama, but watch how the vote breaks down geographically. Can Romney's advantage in GOP-heavy western Iowa overcome Obama's edge in eastern swing territory?

Michigan for long has been considered safe for Obama, but the Republicans have made late gains here.

New Hampshire, the small state, one of the first to vote, is expected to see a cracker finish.

North Carolina is the most conservative of the hotly contested states. Romney appeared to have the late edge in polling. Obama, who narrowly won the state in 2008, has paid less attention to it recently. An Obama victory there could point to broader troubles for Romney.

In the last several elections, between 2 per cent and 3 per cent of Ohio's state's votes came from provisional ballots, which aren't counted until later. In 2004, after a long, tense night counting votes, the presidential race wasn't decided until 11 am the next day, when Democrat John Kerry called President George W. Bush to concede Ohio and the presidency.

Romney desperately needs Ohio; no Republican has won the presidency without it. Without Ohio, Romney would need victories in nearly all the remaining up-for-grabs states and he'd have to pick off key states now leaning Obama's way, such as Wisconsin and Iowa. Obama has more workarounds than Romney if he can't claim Ohio.

Pennsylvania has room for 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 Romney campaigned there on Sunday. No Republican presidential candidate has carried the state in nearly a quarter century.

The outcome in Wisconsin depends on which party is able to inspire more voters to cast their votes on Election Day.

About 4.5 per cent 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.

This is what Pew Research Centre is saying the final figure will be like. But it's still early for us out here.