Trump Backers Bankroll Firm Developing Psychological Profiles of Every U.S. Voter

One of the more mysterious parts of the Mercer family’s political orbit is Cambridge Analytica. The data firm claims it has psychological profiles of over 200 million American voters. The firm was hired by the Trump campaign to help it target its message to potential voters. The Mercers have bankrolled the company and placed Steve Bannon on its board. "Democracy Now!" speaks to The New Yorker’s Jane Mayer.