Behind the scenes at Romney and Obama headquarters

(CBS News) As tens of thousands of voters head to the polls across the country on Tuesday, both campaigns continue the frenetic rush to get their supporters to vote.

CBS News White House correspondent Bill Plante went inside the Obama re-election campaign and spoke with campaign adviser Jim Messina in his first-ever TV interview. The Obama campaign has stressed that they have built a formidable lead in key battleground states through early voting but Messina admits he has had "some sleepless nights" lately. However, he stipulated, "I get paid to worry. The campaign manager spends all his time worrying."

Messina is charged with overseeing the Obama campaign's ground game, the dispatching of thousands of volunteers and paid staffers to knock on doors, make phone calls, and get people to vote early in battleground states. He claims that this grassroots army knocked on 5.2 million doors on the weekend before the election.

"I'm the numbers guy," Messina told Plante. "More people than we hoped have voted and tomorrow we're going to have more people vote than people expect."

According to Messina, their ground game strategy gives Obama "a point or two" lead in states where the election could come down to just a few points.

At Romney campaign headquarters, Plante spoke to Romney's communications director Gail Gitcho who said their candidate is closing strong.

"We've seen this excitement across the country, we think that we have the enthusiasm and the wind in our back," she said.

Gitcho added that the campaign has seen huge crowds of energized voters at rallies and Romney campaign offices across the country. On Election Day, the campaign will activate a system for tracking their efforts to capitalize on this enthusiasm and increase voter turnout among Republicans.

"We're going to have 800 people here in Boston...taking incoming calls from 22,000 to 25,000 people that we're going to have in all states... receiving information on who has voted, what precinct, in what target state," Gitcho explained.

For his part, Messina told Plante that he believes the Obama campaign's get-out-the-vote strategy will come through on Election Day.

"It's all about Tuesday," Messina said before adding, "Someone is going to be right and someone is going to be wrong. And I think we're going to be right."

The campaigns can agree on one thing however: the race will be tight and most voters have already decided, so for both sides, the emphasis remains on getting out the vote before the polls close.