And I want to bring in co-anchor of "good morning america" and anchor of "this week," my co-anchor tonight, george stephanopoulos. Such a night after this long road. What are these two men thinking... See More
And I want to bring in co-anchor of "good morning america" and anchor of "this week," my co-anchor tonight, george stephanopoulos. Such a night after this long road. What are these two men thinking right now? Reporter: Probably exactly the same thing. Tonight, don't take the other guy's bait. Play your game. But there is more pressure on mitt romney tonight. You look at the polls right now, he's behind nationally, probably behind even more in the battleground statements. He needs a circuit breaker and he probably has to do something that gives people that say right now they're voting for the president, to give him a second look. Give all of us a viewer's guide to what they are prepped to do. Reporter: Watch for almost every time mitt romney gets a question, he will try to turn it back to president obama's record. And make president obama bear responsibility for the economy right now, not let him evade it. Mirror image for president obama. Every time he gets a question, he's going to try to focus on mitt romney's plans, governor romney's plans for the future and say, listen, we may not be in the best shape right now, but it's going to be even worse if we implement his plans. Each of them will be pivoting? Reporter: Each time. Here's the thing. Both sides don't really know what's going to happen tonight, because, as david pointed out, this format is so loose. Once they get into the discussion, almost anything can happen. They could directly challenge each other. Jim lehrer could directly challenge them. But they really don't know. It is going to be such an exciting night.
This transcript has been automatically generated and may not be 100% accurate.