In recent months, hysterical opponents of Donald Trump have stoked fears about his candidacy by likening the billionaire to Hitler, raising questions about his mental health, attempting to tie him to the Ku Klux Klan, claiming he may pose a nuclear threat, and warning that a Trump presidency will disrupt international diplomacy and the world order.

While these sentiments might seem novel to most political observers, the template for such attacks may have been set more than five decades ago. All these claims were deployed against Senator Barry Goldwater during his 1964 presidential campaign, which was widely considered a threat to the political establishment.

Countless commentators have compared Trump’s candidacy to Goldwater’s insurgent presidential run. But largely missing from the debate is how Goldwater faced some of the very same attacks made against Trump.

Psychiatrists

In a rare appearance on Fox News on Sunday, Rush Limbaugh noted that Mitt Romney’s father was involved in an attempt to paint Goldwater as a crazed extremist.

Limbaugh stated: “Well, it’s all that and more, but it’s not unprecedented. His dad did much the same thing against Barry Goldwater in a cabal with Republican establishment guys back in 1964. The establishment, this isn’t new. The establishment not wanting outsiders, not wanting conservatives, it isn’t anything new.”

Indeed, the Independent Sentinel reported: “In 1964, liberal Republicans were vehemently opposed to Barry Goldwater’s nomination for the presidency and launched a campaign against him, labeling him a crazed extremist. One of those Republicans was George Romney, Mitt’s father.”

The campaign to distort the public’s perception of Goldwater culminated in an infamous 1964 article in Fact Magazine, which surveyed members of the American Psychiatric Association, or APA, on Goldwater’s mental stability, though none of the psychiatrists had personally examined the presidential candidate.

The New York Times reported on the Goldwater smear:

The survey, highly unscientific even by the standards of the time, was sent to 12,356 psychiatrists, of whom 2,417 responded. The results were published as a special issue: “The Unconscious of a Conservative: A Special Issue on the Mind of Barry Goldwater.”

The psychiatrists’ assessment was brutal. Half of the respondents judged Mr. Goldwater psychologically unfit to be president. They used terms like “megalomaniac,” “paranoid,” and “grossly psychotic,” and some even offered specific diagnoses, including schizophrenia and narcissistic personality disorder.

Only 27 percent of the respondents said Mr. Goldwater was mentally fit, and 23 percent said they didn’t know enough about him to make a judgment.

The Fact article seriously damaged Goldwater’s credibility. It also led to the APA’s so-called Goldwater Rule, which forbids psychiatrists from commenting on someone’s mental status unless they first carry out an examination and the doctor is authorized by the patient to speak to the public.

Despite that ethical standard, slogans similar to the Goldwater smears are being tossed around by medical professionals to describe Trump’s own mental health and his impact on the electorate.

On March 2, the Houston Chronicle ran a story titled, “What psychiatrists make of Donald Trump,” concluding that he suffers from narcissistic personality disorder.

The newspaper claimed:

According to mental-health professionals, Trump’s behavior exemplifies the traits that historically defined the disorder in the Diagnostic and Statistical Manual of Mental Disorders, psychiatry’s bible — grandiosity; an expectation that others will recognize one’s superiority; a lack of empathy. (The disorder was removed from the most recent DSM edition.)

The Chronicle piece was largely based on a Vanity Fair story glaringly titled, “Is Donald Trump Actually a Narcissist? Therapists Weigh In!”

For mental-health professionals, Donald Trump is at once easily diagnosed but slightly confounding. “Remarkably narcissistic,” said developmental psychologist Howard Gardner, a professor at Harvard Graduate School of Education. “Textbook narcissistic personality disorder,” echoed clinical psychologist Ben Michaelis. “He’s so classic that I’m archiving video clips of him to use in workshops because there’s no better example of his characteristics,” said clinical psychologist George Simon, who conducts lectures and seminars on manipulative behavior. “Otherwise, I would have had to hire actors and write vignettes. He’s like a dream come true.”

Last week, the Washington Post ran a scare piece claiming “Psychologists and massage therapists are reporting ‘Trump anxiety’ among clients.” The article received a significant amount of news media attention.

Judith Schweiger Levy, a psychologist on the Upper East Side, told the newspaper that “part of the reason he makes people so anxious is that he has no anxiety himself. It’s frightening. I’m starting to feel anxious just talking about him.”

The Post cited another psychologist, Paul Saks, who practices in Greenwich Village, claiming that reports linking Trump to David Duke, a former grand wizard of the Ku Klux Klan, had worried a patient who is the grandson of Holocaust survivors.

KKK

The David Duke fiasco began with news media claims that the former KKK grand wizard had endorsed Trump. In fact, Duke did not make an official endorsement. In 2015, Duke called Trump the “best of the lot.” After the media reported he had endorsed Trump, Duke wrote on his website, “The Zio Media Lies: I have not endorsed Donald Trump!”

Duke has stated he cannot endorse Trump because of the candidate’s support for Israel.

Last month, Duke expressed support for Trump, although his sentiments were still shy of a formal endorsement. “Voting for these people, voting against Donald Trump at this point, is really treason to your heritage,” Duke stated on his radio show.

Trump has disavowed Duke’s support numerous times, but has still faced media scrutiny because of a CNN interview in which Trump explained he didn’t know about the Duke “endorsement” and therefore couldn’t officially respond. The media has since cited the CNN interview to claim that Trump hesitated to disavow Duke’s so-called endorsement.

“Just so you understand, I don’t know anything about David Duke, OK?” stated Trump on CNN’s State of the Union.

“I don’t know anything about what you’re even talking about with white supremacy or white supremacists,” Trump said. “So I don’t know. I don’t know — did he endorse me, or what’s going on? Because I know nothing about David Duke; I know nothing about white supremacists.”

Attempting to connect Trump to the KKK seems to come straight out of the anti-Goldwater playbook.

One infamous attack ad released by Goldwater’s opponent Lyndon B. Johnson’s campaign was called “KKK for Goldwater.” It portrayed Goldwater as racist because Alabama KKK leader Robert Creel had expressed support for him.

Like Duke’s unsolicited expressions of support for Trump, Creel had urged his supporters to become active and vote for Goldwater.

The New York Herald Tribune News Service quoted Creel saying:

Barry Goldwater is going to be elected. I like Barry Goldwater. I believe what he believes in. I think the same way he thinks. So does George Wallace. But he is only one man, and he can only do so much. They need our help.

Despite Goldwater’s denunciations of Creel, the KKK leader’s support went on to haunt the candidate throughout the 1964 campaign. It even resulted in some Republicans attacking Goldwater, including Baltimore Mayor T. R. McKeldin, who used the KKK’s satisfaction with Goldwater to issue a statement saying, “The greatest shame in the proud history of the Republican party is that racists now find such hope under our banner.”

Hitler

The comparisons of Trump to Hitler, meanwhile, reached a fevered pitch after two former Mexican presidents, Vicente Fox and Felipe Calderon, slammed Trump’s rhetoric against illegal immigration as “racist” and claimed the GOP front-runner is evoking Hitler.

A Google search of mainstream news articles containing the names “Trump” and “Hitler” brings up hundreds of pieces.

On Tuesday, the Jerusalem Post featured an article documenting nine recent times Trump has been compared to Hitler by public personalities, citing remarks by comedian Louie C.K., radio host Glenn Beck, HBO provocateur Bill Maher, and the ladies of ABC’s The View, among others.

On social media, Trump haters have been distributing a photo from a Trump rally in Orlando that shows attendees raising their hands in what opponents call a Nazi salute. In fact, Trump had asked the crowd to raise their hand and pledge to vote for him in the Florida primary.

Goldwater’s critics frequently compared him to Hitler. Jet magazine announced on July 30, 1964, “Barry Goldwater’s Rise is Compared to Rise of Hitler.”

Just prior to the election, union leader George Meany drew attention for comparing Goldwater to the Nazi dictator.

FrontPageMag noted numerous other Goldwater-Hitler smears:

Too many union leaders to count accused Goldwater of Hitlerism and compared him to Hitler and Mussolini. When Nazis supporting George Lincoln Rockwell heckled Goldwater, the media claimed that Goldwater supporters had sent the Nazis to heckle Goldwater.

MLK claimed that, “We see danger signs of Hitlerism in the candidacy of Mr. Goldwater.” Also Khrushchev compared the Republican convention where Goldwater was nominated to a Nazi rally.

Mayor Jack Shelley of San Francisco claimed that Goldwater strategists got all their ideas from Mein Kampf. Roy Wilkins of the NAACP said, “Those who say that the doctrine of ultra-conservatism offers no menace should remember that a man come out of the beer halls of Munich and rallied the forces of rightism in Germany. All the same elements are there in San Francisco now.”

Like Mexico’s leaders with Trump, Soviet Premier Khrushchev in 1964 also compared Goldwater to Hitler.

The AP reported on July 23, 1964:

Khrushchev told a Polish audience that the candidate put forward by the Republican party “made it clear that he wants to enter the White House under the slogans of unbridled anti-communism and war threats.”

He also asserted that the Republican platform, which he denounced as warlike, had been adopted “in an atmosphere reminiscent of the fascist gatherings in Nuremberg.”

Nukes

Trump’s sanity, meanwhile, was called into question by Sen. Marco Rubio, who last month slammed Trump as “a lunatic trying to get a hold of nuclear weapons in America.”

Last week, CNN featured an opinion piece by anti-Trump author Michael D’Antonio titled, “President Trump: A 6-year-old with nuclear weapons?”

Salon ran an article headlined, “Donald Trump could get the nuclear codes: How anti-intellectualism is killing American democracy.”

Perhaps unwittingly, this rhetoric echoes the “Daisy Girl” ad against Goldwater, recently dubbed by USA Today as “the most famous, or notorious, political attack ad in U.S. history.”

In the television ad, considered important to Lyndon B. Johnson’s victory, Johnson’s campaign simulated a nuclear attack on a little girl who is depicted standing in a meadow with a flower in her hand while birds are chirping in the background. The clear implication was that Goldwater could not be trusted with U.S. national security and would bring about a nuclear war with the Soviet Union.

World leaders warn

Besides the harsh, anti-Trump rhetoric from Mexico’s former presidents, there have been reports of unnamed foreign diplomats warning against a Trump presidency, some using the Hitler analogy.

One article that made waves was a Reuters piece on Monday that cited three unnamed U.S. officials who claimed to be quoting unnamed foreign diplomats as expressing alarm “to U.S. government officials about what they say are inflammatory and insulting public statements” by Trump.

Officials from Europe, the Middle East, Latin America, and Asia have complained in recent private conversations, mostly about the xenophobic nature of Trump’s statements, said three U.S. officials, who all declined to be identified.

“As the [Trump] rhetoric has continued, and in some cases amped up, so too have concerns by certain leaders around the world,” said one of the officials.

The three officials declined to disclose a full list of countries whose diplomats have complained, but two said they included India, South Korea, Japan, and Mexico.

James Thurber, a historian who studies U.S. presidents at American University in Washington, told USA Today that such reaction from world leaders is unprecedented.

Perhaps Thurber should study the reaction from world leaders cited anonymously by the news media in 1964 regarding Goldwater.

The Associated Press ran a scare piece in July 1964 quoting foreign news media outlets as well as unnamed foreign officials warning against a Goldwater presidency.

The AP reported:

The Moscow newspaper Sovetsakaya Rossiya declared that Goldwater was backed by a coalition “consisting of the most aggressive capitalist groups, racists, trade union opponents, crusaders of anti-Communism, and Ku Klux Klanners.” …

In Paris, the left leaning Combat described Goldwater as “an irresponsible prospect for president who risks blowing up the world, blowing up Europe, blowing up his own country.”

Reaction in conservative, strongly anti-Communist Spain was mixed.

Several Spanish government officials expressed delight at the nomination.

“Now,” said one, “we will see a real live, hard hitting campaign in the United States.”

Italians heard the news only over the government radio network since all their newspapers are closed by a strike of non-editorial workers.

In Hong Kong, the Chinese Communist newspaper Commercial Daily described Goldwater as an extremist backed by the John Birch Society, the Ku Klux Klan, and Fascists.

The AP followed up with another piece citing more unnamed diplomats fearing Goldwater’s foreign policies:

Misgivings about Goldwater and his publicized views on diplomatic and military policies were expressed in Cairo where African leaders were gathered for a continental summit conference. Some expressed fear that Goldwater could force the United States back to isolation and impede East-West rapprochement.

In India, spokesmen for some political parties viewed Goldwater’s victory as hardly a happy sign for easing world tensions. The governing Congress party was silent.

With research by Brenda J. Elliott.

Aaron Klein is Breitbart’s Jerusalem bureau chief and senior investigative reporter. He is a New York Times bestselling author and hosts the popular weekend talk radio program, “Aaron Klein Investigative Radio.” Follow him on Twitter @AaronKleinShow. Follow him on Facebook.