The Washington Post
March 20, 2013

Less than a decade ago, almost six in ten Americans said gay marriage should be illegal. Today that same six in ten believe it should be legal. That rapid change — particularly on what had long been a divisive social issue — is remarkable in an age of politics where the entrenchment of the two parties seems close to permanent. And, it begs the question: What the heck happened? The answer comes in two parts — one well understood, the other less so.