"But economic class isn’t the only dividing line in America. Many working-class voters are heartland Republicans, while many of America’s superrich are coastal Democrats. The real division is between those who believe the game is rigged against them and those who believe they have a decent shot.
"Losers of rigged games can become very angry, as history has revealed repeatedly. In America, the populist wings of both parties have become more vocal in recent years—the difference being that the populist right blames government more than it does big corporations while the populist left blames big corporations more than government."
Robert Reich in The New York Times says that inequality inflames political polarization.