Deep inside the White House, in a bare room that the chief of staff uses for meetings, David Simas is still thinking about turnout.

As director of public-opinion research and polling for U.S. President Barack Obama's re-election campaign, Simas was at the center of the effort to find and persuade young and minority voters to go to the polls like they did in 2008.

Many doubted the Obama campaign's contention that it could recapture the 2008 electorate. Simas' data, however, convinced the campaign that it was possible. And when the smoke cleared, young voters and minorities did show up to the polls, and Obama won.