There’s much talk about free speech, and the right to it. Now comes a major book explaining who and what is eroding this most basic tenet. Out Monday, it’s “The Silencing: How the Left is Killing Free Speech” by Kirsten Powers, a lifelong liberal and daughter of a feminist who converted to Christianity as an adult and is now a frequent contributor to Fox News. She points out that leftist methodology is to simply shut down public debate with the help of a compliant liberal news media and a secular culture — while squawking about tolerance and values. “It’s easier...