TO WHAT extent does the two-year political investigation into Donald Trump and his top aides and family members, based on suspicions of treacherous “collusion” with the Russian government, represent a kind of McCarthyism? Most people involved in that investigation no doubt would be aghast at the question. After all, they might say, they were only trying to save the country from an obviously bad man who had both motive and opportunity to scheme with the Russians for his own nefarious purposes. Even after Special Counsel Robert Mueller made clear that his two-year investigation could find no evidence of collusion to justify any legal action, many on the anti-Trump Left continued to insist that it had happened and they would continue the assault.

But Mueller’s finding of no collusion does raise questions about the propriety of an inquiry based on suspicions and fragments of evidence that never added up to any serious proof of such cravenness. That was a frequent complaint about McCarthyism back in the days of its greatest menacing influence. And, just as Senator Joseph McCarthy sought to leverage his allegations of communist collusion into partisan political advantage, so too did Trump’s accusers seek to bring down a president and curtail his range of executive action.

TO EXPLORE the issue further, it’s helpful to explore what is meant by McCarthyism. Webster’s defines it as “the use of indiscriminate, often unfounded, accusations, sensationalism, inquisitorial investigative methods, etc., ostensibly in suppression of communism.”

The motive of suppressing communism no longer applies, of course, as the primary sources of anticommunist anxiety in McCarthy’s day—the expansionist Soviet empire and its Chinese counterpart—no longer exist. But today’s obsession with Russia as a threat, although it represents hardly a fragment of the old postwar capacity for menace, could be considered a stand-in for the anti-Soviet obsession of old.

What about “indiscriminate, often unfounded, accusations”? The Russia collusion episode certainly qualifies on that count. Adam Schiff, the California Democrat and ranking member of the House Intelligence Committee (now chairman), said he had “plenty of evidence of collusion or conspiracy”—and, he added, this was “more than circumstantial evidence.” Given Mueller’s ultimate conclusion on the same question, with all of the investigative resources at his command, one has to wonder what evidence Schiff was talking about. Meanwhile, another California Democrat, Eric Swalwell, accused Trump of being an “agent” of Russia. He added, by way of elaboration, “he certainly acts on Russia’s behalf.”

These accusations also comport with Webster’s definitional element of “sensationalism.” But it’s even more sensational and damaging when coming from former top-level intelligence officials, such as James Clapper and John Brennan. Brennan said that “Watergate pales really, in my view, compared to what we’re confronting now.” He described Trump’s claim of no collusion as “hogwash,” which was a roundabout accusation of treason. He dispensed with the circumlocution when he called Trump’s performance in Helsinki, Finland, following a summit with Russian president Vladimir Putin, “nothing short of treasonous.”

Clapper, meanwhile, invoked the constitutional definition of treason when he said Trump was “essentially aiding and abetting the Russians” though he later said he used the term “only in a...colloquial sense,” whatever that means. Asked if Trump was a Russian asset, as former acting FBI Director Andrew McCabe had suggested was possible, Clapper said, “I completely agree with the way Andy characterized it.” He added a “caveat” that it could have been “witting or unwitting.”

Here we get to a fundamental element of McCarthyism, which can be illustrated by an exploration of the real McCarthy and his followers back in the early 1950s. These days we often see, in Hollywood movies and intellectual history, a view of the Wisconsin senator as coming out of the blue, roiling a serene nation with utterly false and brutal accusations of communist activity when there was no such threat at all.

Not so. A couple weeks before McCarthy’s first anticommunism rant, Alger Hiss, accused of passing secret U.S. documents to a Soviet spy when he was a high-level government official, was convicted of perjury. It was a signal victory for the House Committee on Un-American Activities, the communist-hunting panel of Congress, and a great embarrassment for members of the country’s Northeastern elite who had testified on behalf of Hiss’ integrity and patriotism. Two weeks later, the government reported that Klaus Fuchs, a British physicist who had worked at the Los Alamos atomic-weapons facility during the war, had been arrested as a Soviet spy. This was powerful stuff when most Americans believed, correctly, that the U.S. nuclear monopoly had been the margin of security in saving Western Europe from being overrun by the Soviets.

IN OTHER words, McCarthyism is about how people behave even when there is reason for concern or even alarm, as there was in McCarthy’s day. If there was reason to be concerned about Trump’s possible relationship with the Kremlin, that doesn’t excuse abuses of political discourse any more than Hiss and Fuchs served as excuses for McCarthy’s.

Further, in McCarthy’s day, the matter was complicated by the fact that the West’s greatest postwar threat, Bolshevik Russia, had been the West’s great ally during World War II. It was natural that there would be many Soviet sympathizers during that period of close collaboration between America and the Soviet Union. Afterward, of course, everything changed, and many of these sympathizers were caught in the crosswinds. The lingering question was whether some of these people still harbored sympathies toward the Soviets to an extent that constituted a danger to the republic.

No doubt some did, but it was important to draw a distinction between those who had engaged in innocent folly and those who still represented security and loyalty risks. Here we get to Clapper’s “witting or unwitting” caveat regarding Trump.

Clapper, it seems, was seeking to expand the definition of official wrongdoing to ensnare Trump even without any evidence of corrupt intent—in other words, unwitting wrongdoing, like, say, suggesting that it would be good if America and Russia could have cordial relations. We know, based on Clapper’s public pronouncements, what he thinks of that idea. He abhors it because he considers Russia to be a clear and present threat to America. Trump, by contrast, thinks whatever threat Russia poses could possibly be mitigated through efforts to assuage tensions between the two countries.

Here we have a difference of outlook on a fundamental foreign policy issue. But Clapper’s construction of unwitting treachery allows him to leverage that difference of outlook into a brutal allegation of treason even absent any proof of intent. The outlook in itself constitutes prima facie evidence of nefarious behavior—or, as Swalwell and others put it, acting on Russia’s behalf.

HERE WE come to an essential element of McCarthyism, illustrated crisply by one of the first great political conflicts unleashed by the Wisconsin senator and his followers. It concerned the so-called China hands who influenced State Department thinking about Chinese Communism during World War II. The China hands derided the Middle Kingdom’s Nationalist leader Chiang Kai-shek as a hapless and corrupt figure stuck in China’s unsavory past. They glorified Mao Zedong’s communist cadres as disciplined and unsullied “agrarian reformers” who could lead China into the future.

With the advent of the Cold War, however, and with China falling to Mao’s Communist Party in 1949 and aligning itself with Moscow, a rancorous debate ignited over who had allegedly “lost” China.

One of the first to weigh in was the columnist Joseph Alsop, who produced a widely read three-part series on the subject for the Saturday Evening Post, one of the country’s most influential magazines of the day. Alsop had spent most of the war years in China, working for General Claire Chennault, and he had played a major role in the bureaucratic drama centered on U.S. policy toward China amidst war, intrigue, inscrutable motives, mendacity and civic hatreds. He knew what he was talking about, and he faulted the China hands for supreme wrongheadedness. As he summed up his thesis:

Throughout the fateful years in China, the American representatives there actively favored the Chinese communists. They also contributed to the weakness, both political and military, of the Nationalist Government. And in the end, they came close to offering China up to the communists, like a trussed bird on a platter, over four years before the eventual communist triumph.

It’s noteworthy, though, that Alsop took pains to maintain a certain fair-mindedness on the issue. These China hands, he wrote, may have been “injudicious,” but their advocacy was at least “logical, defensible and not indicative of disloyalty” [italics mine]. He singled out particularly John Paton Davies as wanting to wean the Chinese communists away from Kremlin influence, thus conceiving a kind of Titoism in China even before the concept had taken form in Yugoslavia. But ultimately, wrote Alsop, these men undermined the Nationalist regime so thoroughly that any kind of workable, noncommunist government became impossible.

It was a devastating series that, however, avoided any hint of nefarious intent on the part of the men whose actions he disparaged and whose influence he lamented. Thus did he avoid what soon would be dubbed McCarthyism.