In the 75 years since World War II, two imposing demagogues have scarred American public life. One was Joseph R. McCarthy, the subject of Larry Tye’s new book. The highest title McCarthy achieved was junior senator from Wisconsin, but his trail of havoc and personal destruction qualifies him as one of the most despicable political villains of the 20th century.

The second, of course, was President Trump. As Tye points out repeatedly in “Demagogue: The Life and Long Shadow of Senator Joe McCarthy,” the two men have a great deal in common, starting with a gift for fabulation — making stuff up.

Another thing McCarthy and Trump shared was a base of fervent supporters. I was intrigued to discover that similar percentages of American voters stuck with both these demagogues no matter how bad their reputations became. In 1954, soon after the Army-McCarthy hearings that humiliated the senator and a 67-to-22 Senate vote to condemn or censure him, Gallup found that 34 percent of voters still approved of McCarthy. In mid-July of this year, after more than 120,000 American deaths from covid-19, an economic collapse and months of bad publicity for his mishandling of the pandemic, a Washington Post-ABC poll found that 38 percent approved of “the way Trump is handling the coronavirus outbreak” and 39 percent approved of his overall performance as president.

Tye was obviously delighted to discover this quotation from George Gallup, the pollster, describing McCarthy’s devoted supporters in unflattering terms: “Even if it were known that McCarthy had killed five innocent children, they would probably still go along with him.” Was Trump familiar with Gallup’s comment when he said during the 2016 campaign, “I could stand in the middle of Fifth Avenue and shoot somebody, and I wouldn’t lose any voters”? Probably not — Trump has never shown any sign of reading American history. This looks more like a pure coincidence.

But Trump would envy McCarthy’s popularity, which — while it lasted, about five years — was higher than Trump’s has ever been. The senator assembled what Richard Rovere of the New Yorker called “a coalition of the aggrieved.” Polling was much rarer in the early ’50s than it is today, but what polls there were showed that McCarthy, before his fall in 1954, had the support of half the country. Even Dwight D. Eisenhower, an enormously popular president, was afraid to take on McCarthy directly, even after he slimed Gen. George C. Marshall, Ike’s beloved mentor.

One reason for this was the popularity of the anti-communist cause that McCarthy used to try to promote himself into national stardom. McCarthy was actually a latecomer to the anti-communist crusade, which the House Un-American Activities Committee had initiated before World War II. By the time he joined the crusaders in February 1950, at the beginning of his fourth year in the Senate, it was old news. But McCarthy hit on a way to revive it.

He had accepted an invitation to speak to the annual Lincoln Day dinner organized by the Republican ladies of Wheeling, W.Va. On the spur of the moment, Tye tells us, with little preparation or reflection, McCarthy decided to speak on the threat posed by communists working inside the State Department. He had some notes on the subject in his briefcase, alongside notes for a talk on national housing policy — “a snoozer,” according to Tye. The speech McCarthy gave was the first to include the oft-ridiculed phrase “I have here in my hand,” which became a McCarthy favorite. On this occasion what he claimed to have in hand was a list of 205 “members of the Communist Party . . . who are still working and shaping policy in the State Department.”

McCarthy’s personal secretary in 1950 was a woman named Mary Brinkley Driscoll. She refused to talk openly about her boss to her famous brother, the broadcaster David Brinkley, until after the senator died in 1957. David Brinkley recorded their first candid conversation about McCarthy in his memoirs:

“I asked Mary: ‘What did he have in his hand [in Wheeling]? . . . Did he have two hundred and five names?’ Mary: ‘No.’ David: ‘Where did he get that number?’ Mary: ‘He made it up.’ When he saw the headlines his talk was generating, [she went on,] McCarthy ‘was nearly insane with excitement. He clutched the newspapers and ran around the Senate office shouting, ‘I’ve got it. I’ve got it!’ ‘He thought he had the issue he needed to make him into a great political figure and to guarantee his Senate seat forever.’ ”

McCarthy “learned early that there was no worse a penalty for a big lie than for a little one, but that only the big ones drew a crowd, so he told whoppers,” Tye writes.

This is a frustrating, fascinating book. Tye is an inelegant writer and a great reporter. He has relentlessly vacuumed up facts from a rich variety of source materials, some of them never before examined. But his narrative skills are limited, so his book often feels like the result of emptying his notebooks. Tye tells us a lot, but too often he walks away from the biggest mysteries of McCarthy’s life and work with what feels like a defeated shrug, not an explanation. So we never get remotely satisfying conclusions about why McCarthy did what he did in his brief, meteoric career. (He was dead at age 48, a decade after becoming a senator.)

In this long book the author’s most substantial attempt to explain what lay behind McCarthy’s compulsive lying and demagogic behavior is that he suffered from what a law school friend described as a “fantastic” inferiority complex “at the core of [his] personality.” But Tye’s efforts to illuminate that complex seem superficial. Class resentment seems to have been one important demon. Another was sensitivity about growing up in a farm family with parents who never lost their Irish brogues. McCarthy had a first-class mind and sped through high school, college and law school, but he had no intellectual interests. Tye quotes one of his oldest friends: “I don’t think he ever read a book cover to cover.”

But the childhood Tye fleetingly describes was apparently a happy one. McCarthy’s father was no Fred Trump, and his six siblings seem to have loved and admired Joe. Tye calls him “the most talented and good-looking” of the brood, whom his siblings saw “as a standout, even a prodigy.”

On the other hand, McCarthy had a drinking problem from an early age, and by the time he came to Washington in 1947, he was an alcoholic. The senator carried a flask of booze in his briefcase and drank heavily through the workday. Tye tells us about the drinking, but makes scant effort to explain its origins or its impact on the man or his work. His reporting shows that McCarthy must have been drunk for much of the time he was terrorizing Washington. The medical records that Tye uncovered from Bethesda Naval Hospital, where McCarthy was often treated and where he died, reveal that the drinking killed him.

The best chapter in Tye’s book describes how Republicans from Eisenhower to local precinct officials in Wisconsin and nearly every GOP member of the Senate “enabled” McCarthy’s corrupt crusade against communists in government. The account Tye provides is eerily reminiscent of today’s Republicans, whom we are watching in real time as they destroy their party’s future by enabling Trump’s version of demagoguery. Another strong chapter describes the human toll that McCarthy inflicted — the ruined careers and lives that he carelessly sacrificed to his compulsive need for public attention. Thousands of people were affected; some committed suicide.

But Washingtonians old enough to remember the McCarthy years (this reviewer is one) will be disappointed by Tye’s failure to capture the atmosphere the senator created in the nation’s capital, which included fear and loathing but also courage and principle. The McCarthy years were a proud time in the history of this newspaper, whose news columns, editorials and especially its editorial cartoons by the genius Herblock held McCarthy to account day after day. It was Herblock who turned McCarthy into a noun when he coined the term “McCarthyism” in March 1950.

Weirdly, one character in the book connects the McCarthy era — nearly seven decades ago — to the present day: Roy Cohn. McCarthy relied heavily on the young lawyer from New York, who was just 27 when he became chief counsel to the Senate subcommittee on investigations when McCarthy assumed its chairmanship in January 1953. Cohn terrorized many of the people the senator decided needed to be investigated.

Later, Cohn became a Trump family lawyer in New York and a role model for Donald Trump. Cohn was a nasty piece of work who apparently convinced Trump of the benefits of stubborn refusal ever to cooperate with any enemy or competitor who got in his way. For years Trump and Cohn were close, but when the lawyer fell victim to AIDS, Trump dropped him. After finishing this book, one wonders if McCarthy would have done the same.

Demagogue

The Life and Long Shadow of Senator Joe McCarthy

By Larry Tye

Houghton Mifflin Harcourt. 597 pp. $36