US Election: President Obama Casts Early Vote

Barack Obama has become the first president in US election history to cast his vote early.

At this stage of such a tight race, even this has a strategy: the hope is it will boost turnout by offering more chances to vote.

It is estimated 7.2 million people have already cast early ballots and that 35% of the electorate will have already voted by polling day.

The incumbent knows his biggest threat is that those who turned out for him with gusto in 2008 may simply not bother this time round.

In Florida he addressed supporters, brandishing his new glossy 20-page booklet, hoping the plan detailed inside will sway the undecided in his direction.

Swing states like Iowa, Colorado and Nevada have been smothered with affection from both candidates.

Republican challenger Mitt Romney has blitzed all corners of all-important Ohio but, despite a rapturous response from the party faithful, no poll puts him in the lead there.

A loss could prove fatal - no Republican has ever won the White House without taking Ohio.

Republican pollster and strategist David Winston said: "Neither campaign wants to figure out how they win the presidency without Ohio because it'll be a new way to do it and it's always hard to be a first."

Nationwide, the polls remain neck and neck. Taking up or retaining residence in the White House now depends solely on the ground war - unabashed attempts to appeal to all feasible demographics and ultimately selling them an economic plan.

Meanwhile, Mr Obama's communications director Dan Pfeiffer did not deny the president had used the word "b*********r" in a conversation with journalists from Rolling Stone magazine, and insisted: "Trust is a very important part of this election."

An advance copy of Rolling Stone's interview with Mr Obama recounts a chat at the White House between the president and reporters.

"As we left the Oval Office, executive editor Eric Bates told Mr Obama that he had asked his six-year-old if there was anything she wanted him to say to the president," the story recounts.

"After a thoughtful pause, she said, 'Tell him: You can do it.' Mr Obama grinned. 'That's the only advice I need,' he said. 'I do very well, by the way, in that demographic. Ages six to 12? I'm a killer.'

"Thought about lowering the voting age?" Bates joked.

"You know, kids have good instincts," Mr Obama offered. "They look at the other guy and say, 'Well, that's a b*********r, I can tell'."

While this has at times been an ugly campaign, both candidates have been careful to stay professional and presidential. So far Mr Romney's team have not responded. 

Talk of Mr Romney's momentum has been dismissed by the Mr Obama's team and there is a clear effort to cultivate an image of him as a winner.

But, as election day comes ever more sharply into focus, so too does the reality that either Mr Romney or Mr Obama will have to admit defeat, after one of the toughest campaigns in American history.