Polarization
I first heard the term "polarization" in the modern American context in a book The Second Civil War: How Extreme Partisonship has Paralyzed Washington and Polarized America, by political analyst Ronald Brownstein, published in 2007. Again and again, Brownstein frets over important elections decided by "razor-thin margins". The lack of common ground, expressed by politcal-party loyalty and the absence of cross-voters in Congress, suggests deep divisions in the body-politic, although the voters don't like cross-overs by politicians who represent them.
