Ben Carson, retired neurosurgeon, speaks during the Republican National Convention (RNC) in Cleveland, Ohio, U.S., on Tuesday, July 19, 2016. Donald Trump sought to use a speech by his wife to move beyond delegate discontent at the Republican National Convention, only to have the second day open with an onslaught of accusations that his wife's speech lifted phrases from one delivered by Michelle Obama in 2008. Photographer: Andrew Harrer/Bloomberg Image Credit: Bloomberg

To the serial dishonesty, overt racism and jaw-dropping sexism, we can now add a new, more subtle layer of shame to Donald Trump’s campaign to be the president of America: The relentless exploitation of genuine grief and heart-breaking pain. The first night of the Republican convention in Cleveland was devoted to a simple theme: Make America Safe Again. But that idea was pursued not by the presentation of a new law-and-order policy or a fresh military doctrine, but by a procession of grieving parents and siblings, telling of the soldiers or victims of crime they had lost over the past eight years — and blaming Hillary Clinton, along with President Barack Obama, for their deaths. Two mothers and a father described sons they had lost to killers whom they described as “illegal aliens”.

Their voices choked with emotion as they described the loss they had suffered. And each attributed that loss to the Obama administration, for failing to keep out the people who had killed their children. In the words of Mary Mendoza, whose son was killed by a drunk driver who had entered the US illegally: “A vote for Hillary is putting all our children’s lives at risk. It’s time for Donald Trump.”

No one who heard them speak could deny the depth of their agony. And of course such testimony is powerful, but it felt like an appalling abuse of their suffering. Nowhere was that clearer than in the case of Pat Smith, whose son Sean was lost in the terrorist attack on the United States consulate in Benghazi, Libya, on September 11, 2012, when Hillary was secretary of state. Smith’s distress was plain to see, her voice choked by the torment of mourning. And her target was direct. “I blame Hillary Clinton personally for the death of my son,” she said. “How could she do this to me?” Later she repeated the chants rising up from the floor: “Hillary for Prison!”

No one forced Smith onto the platform in Cleveland. Yet, it felt all wrong. There is a reason we speak of people being “crazed by grief”. It is because we understand that those in deep anguish will often seek to channel their pain by blaming not a distant target, but one closer to home. We understand that. But we don’t exploit it by putting a person in the grip of such horror on a national stage.

The Trump campaign would counter that the Benghazi case against Hillary is hardly irrational, insisting that the soldiers who might have protected those US diplomats in danger were ordered instead to “stand down” — a decision that, they argue, makes Hillary culpable for the deaths that followed. Indeed, that claim was repeated by two subsequent speakers in Cleveland — a pair of former US marines involved in Benghazi. The trouble is, that “stand down” allegation has been thoroughly debunked, most directly by the Republicans’ own House investigation. (Similarly, there’s no evidence that illegal immigration has caused an explosion in crime.)

But it was the tactic itself, rather than any dubious accuracy, that was the problem. As the Daily Beast’s Mike Tomasky asked, how many parents of the 241 US marines killed in a terrorist attack in Beirut in 1983 were guest speakers at the Democratic convention in 1984?

No doubt there would have been mothers and fathers ready to blame former president Ronald Reagan personally for their bereavement. But to use that grief would have felt too much like exploitation. Nor did Democrats invite the families of US soldiers slain in the Iraq war on stage in 2004, even though they would have had every right to blame George W. Bush as he sought re-election. Republicans would have accused their opponents of contemptible shroud-waving if they had.

One has to go back to another former president, Richard Nixon’s deployment of the families of prisoners of war and US soldiers missing in action in Vietnam to find a similar act of exploitation. But Trump’s move felt cruder.

Will it be effective? Polls suggest Benghazi, though a perennial Fox News obsession, does not animate too many voters.

And there’s something else too that may dampen the impact. While Smith was addressing the hall in Cleveland, Trump was elsewhere. He was on Fox News, in fact. Giving an interview at exactly the same time, thereby treading all over the story the convention was trying to build. It was a reminder that a shameless willingness to exploit suffering is hardly Trump’s only vice. When it comes to the Republican nominee, narcissism always trumps the rest.

— Guardian News & Media Ltd

Jonathan Freedland has published eight books, including six best-selling thrillers, the latest being The 3rd Woman.