On August 11, 2009, it was announced in the Portland Press Herald that Mitchell had filed the paperwork to run for Governor of Maine in 2010.
She faced Republican Paul LePage, and Independent candidates Eliot Cutler, Shawn Moody, and Kevin Scott.
Mitchell remarked, "I will be supportive of the next governor, whoever that is" — alluding that it was still uncertain at that hour whether Cutler or LePage would win the race.
[5] With 94% of precincts reporting on the day after the election, the Bangor Daily News declared LePage the winner, carrying 38.1% of the votes.
On June 25, 2010, Mitchell was endorsed by the Maine Education Association, which is the state's teachers' union.