The hired hands CBS picked to investigate its “60 Minutes” debacle may deny it till the cows come home. But liberal bias ruined the career of Dan Rather—and CBS News. The CBS of Walter Cronkite’s salad days is gone. And the beginning of the fall of network news can be traced to that era, right down to the day and month. After his address to the nation on Nov. 3, 1969 that called on the “silent majority” to stand by him for peace with honor in Vietnam was savaged by network anchors and commentators, an infuriated Richard Nixon ordered his...