Over the years I have read several articles that use the concept of "reactive ethnicity". This describes the way ethnic identity and attachment is heightened when members of that racial/ethnic group perceive discriminatory threats.
I think we can use this general idea to describe a major dynamic in the 2012 Presidential election -- "reactive voting". In this case, voting was stimulated by perceived threats of suppression by largely Republican forces in many states. Paradoxically, while there was a clear enthusiasm gap among many voters for Obama in 2012 versus 2008 that would have dampened voter turnout, the effort to suppress the vote actually mobilized voters to get to the polls and cast a vote come hell or highwater. The long lines and the willingness of people to wait up to 6 hours was well-documented in the media.
For the Republicans, this result confirms beautifully the most durable and essential of all sociological concepts -- the law of unintended consequences. The purposive action to suppress voter turnout and facilitate a Republican victory had exactly the opposite effect. Is it possible that the act of suppression actually contributed to the victory?