There's a sad symmetry in that my second to last Herald column takes me back to the subject of my second written in April 2004: jihadist terror.

Back then I quoted a character in my 1996 novel Guerilla Season who predicted that Islamist militants were about to launch an undeclared war on the West. "The jihadists' serene preparedness to push the envelope of atrocity," I wrote, "condemns us to living in terrifying times."

(The character, a Rainbow Warrior-related terrorist, was wrong in one sense: in 1998 Osama bin Laden issued an overt declaration of war, declaring that "killing Americans and their allies - civilian and military - is an individual duty for every Muslim who can do it in any country in which it is possible to do it.")

I rehash not to pat myself on the back for prescience but to highlight the preposterousness (the vileness is a given) of Donald Trump's post-Orlando massacre tweets congratulating himself for having warned of the Islamist terror threat.


He went on to imply that Barack Obama isn't doing more to stop such attacks because he secretly sympathises with the killers and may be in cahoots with Isis.

While it's been obvious from the outset that Trump is professionally unqualified and personally unfit to be president, there's been an undercurrent of reluctant approval in some media commentary and the wider discourse.

You know the sort of thing: "You've got to admire someone who's so politically incorrect." Or: "No one could ever accuse him of being dull."

However, suggesting the President's sympathies are with those who slaughter innocent young people cannot be soft-pedalled as theatricality or buffoonery. It's sinister but not unprecedented in that it harks back to the witch-hunt, launched in 1950 by Senator Joe McCarthy, to root out communist sympathisers embedded at the heart of the American government.

It's no coincidence that Trump surrogate Roger Stone followed up by recycling discredited claims that Hillary Clinton's top aide Huma Abedin could be a "Saudi spy or terrorist agent". (Abedin, a Muslim, was born in Michigan to an Indian father and Pakistani mother and spent her childhood in Saudi Arabia.)

Nor is it a coincidence that Stone, a veteran of Richard Nixon's dirty tricks operation, and Trump himself are proteges of the malevolent Roy Cohn who, as general counsel to the Senate Permanent Subcommittee on Investigations, was McCarthy's attack dog.

In private practice Cohn helped the young Trump navigate the murky waters of the construction and casino industries in New York and New Jersey. It probably helped that Cohn's other clients included mafia bosses, notably the notorious John Gotti, whose influence permeated those industries.

One assumes the Democrats will be more forthright on the subject of Trump's dealings with the mafia than his Republican rivals were.

Cohn was an anti-Semitic Jew and a homophobic homosexual. His and McCarthy's scare campaign against communists segued into persecution of homosexuals - the so-called Lavender Scare - that in 1953 led to President Dwight Eisenhower banning homosexuals from working for the federal government.

Cohn's last live-in lover was Peter Fraser, who grew up on a New Zealand farm and at 19 set off to see the world. He met Cohn, who was more than twice his age, at a party in Mexico and shortly thereafter moved into his 33-room Manhattan townhouse.

In what may be the only recorded instance of Cohn displaying a sense of humour that wasn't malicious, Cohn introduced his lover at a New York society luncheon as "Sir" Peter Fraser. The following day a gossip columnist reported that the former New Zealand prime minister had been among the guests. (The real Sir Peter Fraser was Prime Minister of New Zealand from 1940 to 1949.)

Journalist and author Nicholas von Hoffman wrote an acclaimed biography of Cohn, who died of Aids in 1986, aged 59. But despite his years of research, von Hoffman couldn't provide a definitive answer to the question he posed in book tour interviews: "How could a man so morally repugnant get away with it?"

Part of the answer, surely, is that Cohn primarily operated behind the scenes, a malign puppet master.

A more troubling question is how could someone so morally repugnant who has lived his life in the hot glare of publicity get away with being a candidate for the most important political office in the world?