By distinguished Stanford political scientist Morris Fiorina. I'm not convinced yet, but this is an undeniably important and interesting perspective.
To understand contemporary American political life, you should begin with the realization that most of the people blabbering on cable television, venting on Facebook, and/or fulminating on Twitter are abnormal. They are abnormally interested and involved in politics, they tend to occupy the policy extremes, and they are abnormally opinionated . . .
Turning from interest and activity to beliefs and preferences, an examination of the ideological distribution of the American public finds that roughly 40 percent consider themselves moderates, 35 percent conservatives and 25 percent liberals. These figures are virtually the same as those from 1976, when the Democrats nominated an Evangelical Christian from Georgia and the Republicans a country club moderate from Michigan. On issue after issue the American public chooses centrist positions.