Things were obviously getting a bit frenzied. For starters, the Soviets had figured out how to make an atomic bomb, China had gone communist, and at home politics were being whipped into a froth by charges and countercharges of "un-Americanism." Like most historians since then, the Alsops blamed much of the era's craziness on Sen. Joe McCarthy, who a few months earlier had launched his anti-communist smear campaign in Wheeling, W.Va., by brandishing a bogus list of "subversives" in the State Department.

But the causes of the hysteria were much more complex than that -- and began long before the term "McCarthyism" was first used in print (by Herblock in a 1950 Washington Post editorial cartoon). Looking back from half a century later, Michael J. Ybarra, a former staff writer for the Wall Street Journal, borrowed part of the Alsops' title for his richly researched, endlessly entertaining chronicle of what might have been the 20th century's most tragic, self-destructive politics. He traces the origins of the period's hysteria to "a conservative reaction" to the new deal fueled by "rural rancor toward urban elites, nativist dread of encroaching minorities, fundamentalist anxiety over the spread of secular values" and Jeffersonian scorn for a growing and activist government."

In Ybarra's telling, no one embodied these fears and antipathies more than Sen. Patrick McCarran, a Democrat from Nevada who wielded extraordinary influence as chair of the Senate Judiciary Committee. His corrupt, sometimes crazed, hopelessly reactionary career is the centerpiece of Ybarra's tale.

"Years before Joe McCarthy ever opened his mouth in public," writes Ybarra, "McCarran believed -- really believed -- that the Democratic Party was controlled by the Communists and that one mysterious person especially had managed to exert a malign influence that could be felt at the highest levels of government." He once told a friend, "If I . . . eventually find that one, I will have served my country well."

The senator's early years gave no hint of the direction his life would take. The son of illiterate Irish immigrants, he started out as a populist, the law partner of a socialist and a friend of the working class. Correctly viewed as an outsider in Nevada's feudal political circles, he had a painfully sluggish beginning in politics. Once elected as a Democrat, he maintained just enough party allegiance to keep federal boondoggles coming to Nevada. In 1944, he became chairman of the Judiciary Committee and thereby one of the most powerful men in Washington. Four of every 10 bills had to go through his committee. He also controlled the subcommittee handling budgets for the State and Justice departments.

He ruled like a sultan. One year he cut State Department funds by $20 million because it circulated Herblock cartoons ridiculing him. He used FBI agents as chauffeurs and tourist guides for his wife and five children. The senator was apparently too powerful to be indicted even though he clearly committed perjury when, despite wiretap evidence to the contrary, he repeatedly swore he had never dealt with mobster Bugsy Siegel. There were serious stories of McCarran's being paid off at fixed roulette tables for blocking a federal tax on gambling.

"From the oversized chair in the Judiciary Committee room," writes Ybarra, "McCarran ran a virtual government-in-opposition, even while his own party controlled the White House and both wings of the Capitol," and he used his power ruthlessly. He turned Truman's attorneys general into puppets, driving the president into such a rage that he declared Nevada was a meaningless "hell on earth" that "should never have been made a state." He had a point. McCarran represented the least populated state in the nation. He needed only a piddling 35,000 votes to be elected, yet Senate rules gave him the power to cripple major portions of the federal government and shred the Constitution.

Laws that McCarran wrote and pushed through Congress made it easy to fire federal employees without telling them why or giving them a way to appeal and set up concentration camps in this country for imprisoning left-wing dissidents during "emergencies." With the end of World War II, there were seven million Europeans homeless and adrift. McCarran considered all immigrants to be potential spies, and he hated Jews. Using the McCarran-Walters Immigration Act and his Internal Security Act of 1950 to tighten immigration, he limited the number of refugees to only half a million over a two-year period -- fewer than 10,000 were Jews.

In 1951 McCarran created the Senate Internal Security Subcommittee "to investigate subversive activities" and named himself chairman. Although the House Un-American Activities Committee got much more publicity, the SISS was a goon squad, "the most fearsome of the congressional investigating committees in mid-twentieth century America." In 1954, McCarran keeled over dead from a heart attack in the middle of a political gathering. Thousands, including seven conservative senators, were there for his funeral in Nevada and for the valedictory speeches that followed. Sen. Styles Bridges, who had been McCarran's point man in many a witch hunt, said: "Any person with a personality can acquire friends, but only great men with the characteristics of Pat McCarran acquire enemies. I admire him for a great many things, not the least of which was the cluster of enemies he had."

It was a rather large cluster. Perhaps speaking for it was a local reporter attending the same event. Ybarra tells us he grumbled, "McCarran was a son of a bitch alive and he's a son of a bitch dead."