President Obama trying to avoid miscue in first debate

"This is a guy who will not back off delivering the negative and that's not the easiest thing to do," said Tad Devine, a Democratic strategist who is not working with Obama's team but advised the late Massachusetts Sen. Edward M. Kennedy in his 1994 Senate campaign against Romney.

Obama and Massachusetts Sen. John Kerry, who is playing Romney, have held several lengthy debate preparation sessions at the Democratic National Committee headquarters, a short drive away from the White House. Former White House aides Anita Dunn and Ron Klain have been brought in to help run the sessions.

Obama's preparations here in Nevada are expected to mirror his approach from 2008, when he got ready for the first debate against McCain at a hotel in Palm Beach, Fla. Obama's campaign held daylong preparation sessions that included mock debates starting at 9 p.m., the same time as the actual debate. The practice debates were held on a replica of the debate stage "practically right down to the carpeting," White House adviser David Plouffe wrote in his 2009 book, "The Audacity to Win."

The president's team picked Nevada for this year's debate camp in part because it's one of the eight or so battleground states that will determine the election. Obama held a campaign rally in Las Vegas Sunday night and plans to make a few stops around the area during his stay, all aimed at driving local media coverage.

Others leading Obama's debate prep include senior campaign adviser David Axelrod, White House communications director Dan Pfeiffer and top economic adviser Gene Sperling. Obama's chief of staff Jack Lew, campaign pollster Joel Benenson and speechwriter Jon Favreau are also assisting the president.

Thomas reported from Washington.

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