Morgan doesn’t minimize the Red threat. He relies on decoded Soviet cable traffic, released only in 1995, which confirms much of what the American left has deemed paranoid fantasy. But by 1950, when McCarthy started his crusade, the communists had been largely disabled by the House Un-American Activities Committee and the 1940s anti-sedition Smith Act. The McCarthy horror show, which destroyed careers and lives–including McCarthy’s–had more to do with partisanship and personal pathology than with patriotism. Yet Morgan’s contempt is evenhanded: he’s no harder on McCarthy than on such left-wing pietists as the often sentimentalized Hollywood Ten; he calls screenwriter Dalton Trumbo a “money-grubber” with “a veneer of militancy.” You don’t agree with all his judgments? Well, it’s a free country, knock wood.