I try to avoid sending out political stories that may appear overly partisan in nature, but having read Sahsha Issenberg's book, The Victory Lab, I know that he reports carefully on data use by both democrats and republicans (I mailed the book to our resident former Republican congressional candidate Ethan Wingfield). This is a great story on the use of random experiments in voter contact, persuasion and turnout and seeming advantage that Democrats have on this front:
In fact, when it comes to the use of voter data and analytics, the two sides appear to be as unmatched as they have ever been on a specific electioneering tactic in the modern campaign era. No party ever has ever had such a durable structural advantage over the other on polling, making television ads, or fundraising, for example. And the reason may be that the most important developments in how to analyze voter behavior has not emerged from within the political profession.