Ten years ago this coming February, George Zimmermann shot and killed 17-year-old Trayvon Martin on a rainy night in Sanford, Florida. Without intending, Zimmerman triggered a dark new phase in the history of progressive America. Beginning with the Sacco and Vanzetti case in the 1920s, the left lied to conceal the guilt of the guilty. Yes, Virginia, those two bad boys were guilty. Upton Sinclair, who “proved” their innocence in his epic novel Boston, knew they were guilty. "My wife is absolutely certain that if I tell what I believe,” Sinclair confided to a friend, “I will be called a...