Early exit polls about three hours before the last polls close in Michigan‘s primary show frustration with the Republican field and hints of mischief among Democratic voters.

According to those who responded to questioners, less than half of those voting in the Republican primary said they strongly favor their own candidate.

While six in 10 voters identified themselves as Republicans, one in 10 of those voting in the GOP primary said they were Democrats. Michigan has an open primary where voters can choose without regard to party affiliation.

One in four respondents say they made up their mind in the last few days and six in 10 said the CNN debate last week was a factor in their decision.

Michigan is seen as a key state for Mitt Romney, who was born in Detroit and whose father was governor of the state. The GOP field is also competing tonight in the Arizona primary.

Tune in to CNN TV now for live co verage of the Arizona and Michigan primaries and follow real-time results onCNNPolitics.com, on CNN’s apps and on CNN’s mobile website. Follow CNN Politics on Facebook and on Twitter at #cnnelections.