And with the race this close tonight, it will all come down to which campaign can get the vote out. In one cleveland suburb today, we discovered that dueling campaigns can actually watch one another... See More
And with the race this close tonight, it will all come down to which campaign can get the vote out. In one cleveland suburb today, we discovered that dueling campaigns can actually watch one another from across the street. We're here at the obama-biden field office in one of the suburbs surrounding cleveland, and just to give you an idea of how crucial these votes are in the suburbs, how competitive both campaigns are for these votes, I wanted to show you how long it would take us to get from the obama field office to the romney field office. We literally drove down the parking lot and, well, look across the street. There's romney-ryan. How are you? Good to see you. Reporter: Few days left. And that's where we started, with the team trying to unseat the president. And they know they need ohio. Inside, you can sense it. They know they have just few precious hours left. So, this is the buzz, two days out. May I please speak with michael? Reporter: Volunteers calling lists of voters who they believe lean republican. So, the people you are calling right now, you have a hint they could be leaning republican, you just need to get in touch with them. That's exactly right. Reporter: President obama won this county four years ago. George w. Bush won it in 2004 and they are determined to flip it back. Tom gave up his sunday with his family to knock on doors. Are you missing a game to do this? Well, you know, I have a radio in the car, so -- Reporter: You'll have the score. That score tuesday night more important to him. Well, I think we're at a very critical point, a historic election. Reporter: We ride with him in a small team of volunteers to find the undecided voters. The romney campaign telling us they believe that's a pool of just 2% of ohio voters, perhaps even less. They find one. I haven't made up my mind yet. Reporter: Russ, a dad, an electrician. How many times have you been called or contacted? Quite a few times. Reporter: Tonight, he says he's leaning obama, telling me help for the middle class is most important to him. But the romney team not giving up. This is a gentleman who says he's been contacted several times by both you guys and the obama team. Ook, I mean, we're not taking absolutely anything for granted. Reporter: Nor is the team inside that obama field office, back across the street. How are you doing? In one of the back rooms, you n't hear phones ringing. Instead, you hear the printer. Printing up sacks of maps. They call it cutting the turf. And this one turf alone, how many houses? This is 15 or 20. Reporter: And every one of them, a voter who they believe if they meet them face to face, will vote for the president. Every dot on this map is going to be someone who gets a knock today. Yep. And tomorrow and tuesday. Reporter: They're goi to love you in that neighborhood. David, a grandfather, says he's knocking on doors for his grandchildren's future. And he finds this woman, he asks her if he'll vote early but she says she wants to stand in line on election day.
This transcript has been automatically generated and may not be 100% accurate.