By Cian McCormack in Virginia

It’s been a gruelling campaign, not just for Barack Obama and Mitt Romney, but also for the armies of volunteers working tirelessly behind the scenes.

In Virginia, the Democrats are getting to the doorsteps by busing in young “surrogate” canvassers from Washington DC.

Lynn Schneider, an attorney from California, based herself in Norfolk for the election. She says: “Every vote is precious for every citizen, but especially in a state like Virginia.”

The Republicans are pushing hard too. Romney is calling for his supporters to “reach across their yards” to convince their next-door neighbours to vote for him.

There’s a common philosophy on both sides – you’ve got to get your voters to the polls or your candidate won’t cross the line first.

That’s why over the weekend – and even during the last day of the 2012 campaign – Obama and Romney have frenetically dipped in and out of swing states at break-neck speed.

Both candidates are greatly aware they need to motivate and electrify their base to gain voting advantage.

So, in an election like this one – where polls are putting both candidates at 48% in the swing states – you’ll see canvassers, both surrogate and local, swarming through the swing states in great numbers knocking on doors, calling to neighbours, doing everything they can to get their people to the polling station.

There’s a good reason for this: Turnout.

Quentin Kidd, Professor of Political Science at Christopher Newport University, says it’s all down to demographics and getting the right people to the polls.

It’s simple. A voter may promise to vote for a candidate, but it doesn’t mean they’ll actually turn up to vote on the day.

Professor Kidd knows this and he expects turnout to be lower than in 2008.

“It was 61-62% last time. I don’t think it will be that high this time. It’ll be in the upper 50s,” he said.

It’s expected that African-American voters will turn out in great numbers as they did before.

“They feel very proud of [Obama]. They feel very defensive of him. They want to turn out and be supportive of him,” Professor Kidd said.

There could be an advantage to Romney though.

Younger voters may not drift to Obama in the same numbers as they did before.

Professor Kidd says in 2008 Obama sparked the young person’s imagination, but this time he’s not new.

“He’s got four years worth of scars,” said the professor. “He’s got grey hair. They are also four years older and they’ve also suffered through this bad economy. I think that they are also a little demoralised.”

With an eroded youth base, the Obama campaign will be hoping to capitalise on the growing Latino vote in some swing states – Virginia, Nevada, and North Carolina.

Professor Kidd expects that vote to be twice what it was in 2008.

In a state such as Virginia that makes a big difference as 8% of eligible voters are Latino.

“Last time they turned out at 2%,” says Professor Kidd. “This time if they turn out at 3, 4 or 5% that makes a big difference. I think the Obama campaign is banking on that.”