The reemergence of a Democratic left will be one of the major stories of 2014. Moderates, don’t be alarmed. The return of a viable, vocal left will actually be good news for the political center. For a long time, the American conversation has been terribly distorted because an active, uncompromising political right has not had to face a comparably influential left. As a result, our entire debate has been dragged in a conservative direction, meaning that the center has been pulled that way, too.