The Associated Press reports that the 50 staffers deployed to North Dakota are being dispatched to Minnesota and Wisconsin.
Obama campaign manager David Plouffe earlier this month confirmed reports that the campaign had shifted staff from Georgia to North Carolina.
Of the other states President Bush won in 2004, Obama is still competing in Colorado, New Mexico, Nevada, Iowa, Ohio, Florida, Montana, Missouri, Indiana, Virginia, and the Tarheel State, the campaign says.*
* This post has been updated.