These results are for likely voters, who are the respondents Gallup deems most likely to vote based on their responses to a series of questions asking about current voting intentions, thought given to the election, and past voting behavior. Each seven-day rolling average is based on telephone interviews with approximately 2,700 likely voters; margin of error is ±2 percentage points.
http://www.gallup.com/poll/157817/election-2012-likely-voters-trial-heat-obama-romney.aspx
http://www.gallup.com/poll/157817/election-2012-likely-voters-trial-heat-obama-romney.aspx
