and slate columnist sasha issenberg, author of the book, "the victory lab, the secret science of winningpaigns." now in new york city. carol leigh let me start with you. at what point did the obama campaign, did the obama team begin to think about how they wanted to position themselveses and how did they do it? >> very early. they-- the first step that they took was to determine that they were going to run in a terrible economy, and they needed a message that would be sailiable, regardless of what was happening in the economy, so they settled on this notion that they wanted to make the election about a choice, where voters were going to look and decide which candidate was going to stick up for them. and that's why the president hammer on the middle class message. that was an early decision. >> woodruff: even before they knew who their opponent was. >> exactly. their opponent they always assumed was going to be the economy essentially. as time moved on and they figured it was definitely going to be romney they zeroed in on him. and there were a couple of pivotal moments throughout the cam

. >> woodruff: sasha issenberg, i want to bring you into this.nwhile, while all this strategy plan was going on, in terms of a ground game, the big papi information decided very early on they were going to do-- take something they had started in 2008, and bear down on it. tell us very quickly how that worked. >> this is basic alone an instance of tactic informing strategy. the obama campaign thought of this as a mobilization election. thait they had to put together the coalition from 2008. part of the electorate that traditionally vote at a low rate and reengage them and mobilize them-- young people and minorities, in particular. what they had on their side was a whole bunch of new tools. they start running randomized controlled experiments, basically field experiments, that allowed them to understand what actually moved voters. and they came up with a sort of body of knowledge, not only about specific issues that would persuade voters, little bits of messaging, but they came to understand i think a whole lot more about what the value of an indiv