Tuesday's debate in Hempstead, New York, is being conducted in a town hall debate style, with a panel of 82 undecided voters posing questions to the candidates.

Obama is expected to be on the offensive after appearing to hold back during the first debate two weeks ago. Some critics say he was soft on Romney, who was declared the winner of that debate.

CNN's Candy Crowley is acting as moderator for the debate, which is scheduled to last for 90 minutes.

mz/jm (Reuters, AFP)