The IRS has been credibly accused of targeting conservatives as a way to minimize their participation in the 2014 elections. But there is a mirror image to their suppression in the last cycle; the Obama campaign's utilization of Big Data to bring liberal partisans to the polls.
It was something that the press writing of admiringly both before and after the election, for example:
Businessweek: Google's Eric Schmidt Invests in Obama's Big-Data Brains
Other outlets have confessed to some trepidation: