Obama will hit a fifth state, Michigan, which has a competitive governor's race, along the way. "President Obama remains able to unite base Democrats, persuadable voters, and to motivate demographics less likely to turn out in midterm elections like young people," said Ben LaBolt, who served as spokesman for the first Black president's successful 2012 re-election campaign. "Bringing in President Obama helps to underscore the importance of African-American vote, while also exciting other voters." But Democrats will have to wonder if that will be enough, as recent polling has shown Republican candidates gaining strength across the board. The Senate race is Georgia is essentially tied, even as Walker has been hamstrung by a series of controversies.

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