There were to be many black-bordered pages in U.S. newspapers on Friday, Nov. 22, 1963, and for days afterwards.One appeared before the president was even shot.

As if by way of premonition, President John F. Kennedy saw the first of them over coffee in his Fort Worth hotel room on the last morning of his life. It darkened his mood. “We’re heading into nut country today,” he told his wife Jackie ahead of the short hop on Air Force One to Dallas.

The thick black border surrounded a full-page ad – a 650-word attack on his administration’s domestic and foreign policies – in the Dallas Morning News. Paid for by three members of the far-right John Birch Society, it was headed, mockingly, “Welcome Mr. Kennedy to Dallas.” The unsigned “Wanted for Treason” handbill (reproduced here), paid for by a supporter of the right-wing General Edwin Walker and distributed on the eve of the assassination, also became notorious.

The president was in Texas to mend fences between liberal and conservative personalities in the Democratic Party. In Dallas, though, the main political factions were conservative and ultraconservative Republicans, according to scholar Edward Miller’s “Nut Country: Right Wing Dallas and the Birth of the Southern Strategy” (published last year in hardcover and this summer in paperback).

During the 1960 campaign, vice-presidential candidate Lyndon Johnson and his wife were jostled and spat upon in Dallas. And, in October 1963, just a month before the president and vice-president’s visit to the city, UN Ambassador Adlai Stevenson was hit over the head with a placard. He warned the president about the “ugly and frightening” mood there.

An article in Fortune magazine shortly after the assassination referred to Dallas as “the hate capital of the nation,” and “a place so steeped in violence and political extremism that school children would cheer the president’s death.”

In a 14-minute New York Times documentary by filmmaker Errol Morris, posted on Nov. 21, 2013, investigator and author Josiah “Tink” Thompson recalled the cognitive dissonance experienced when it turned out that it was “some Marxist sympathizer nutcase, in Dallas of all places, who decided to shoot the president.”

That, together with the murder by Jack Ruby two days later of the accused assassin Lee H. Oswald, fueled conspiracy theories from the get-go. Many who resisted the notion of a conspiracy, however, did speculate that the unbalanced Oswald, a proclaimed pro-Castro leftist, may have been pushed over the edge by the toxic anti-Kennedy atmosphere in right-wing Dallas.

Historian William Manchester, who was handpicked by Mrs. Kennedy to write “Death of a President,” was one who gave the idea much credence in his 1967 volume.

One wonders whether a kind of Oswald syndrome was at work over the past couple of weeks, when we saw the anti-Hillary Clinton rhetoric of the RNC in Cleveland spill over into streets of Philadelphia during the DNC. The chant of “Lock her up” promoted by right wingers, for example, was taken up by the Bernie-or-Busters.

News outlets had no problem finding left-wing protesters in Philly willing to go on the record with misogynistic epithets directed at the presumptive Democratic nominee.

American politics has always been robust, of course, but the toxicity of the Dallas Morning News' full-page ad and that handbill – both of which set a sort of thematic template that’s still used – has become more mainstream and 24-7, via cable news and talk radio. The good news is that there is a great deal more fact-checking, if you’re interested.

And so when Gov. Chris Christie took on Hillary’s foreign policy record in his RNC slot, the New York Times declared it “mostly fact-based,” but “selective” and “often ignoring exculpatory evidence.” This might have been a good summary of his comments on the Libyan intervention (which Donald Trump supported), but overall it let the New Jersey governor off very lightly.

Fred Kaplan on Slate.com wasn’t alone in invoking the Salem Witch Trials of the late 17th century and Arthur Miller’s play about the episode: “This [Christie’s] reading seemed more like an audition for the role of Reverend Parris in a summer-stock production ‘The Crucible.’”

Of course, it’s more likely that Christie was actually up for a certain part in the cabinet. Kaplan, author of “Dark Territory: The Secret History of Cyber War,” added: “In this light, he wouldn’t make it as an assistant district attorney in Cuyahoga County, Ohio, much less as attorney general of the United States.”

He went on to outline a quite devastating take-down of Christie’s “bill of indictment,” showing that on Nigeria, Iran, Cuba, Syria and Russia, the exculpatory evidence simply made a nonsense of the charges.

But then the “witches” of Salem in the play and in history were innocent, too.

The inflamed atmosphere today with Trumpism is mirrored in the hate towards JFK back in 1963. America has moved on in so many ways but vicious political attacks have not changed.