Leaders should stop thinking their electorate are stupid and and own up to blunders they make.

When he assumed the presidency, he was widely regarded – to borrow a phrase from Helen Zille – as “unfit for purpose”.

He was relatively undereducated and the product of a corrupt political machine. He was only picked for the No2 spot in the presidency to placate warring ruling party factions. His predecessor was regarded as a political colossus and was, perhaps, for much of the 20thcentury, the most admired leader in the world.

I refer to the 33rd president of the US, Harry S Truman. He was an accidental president who initially succeeded to office only because his sainted predecessor, Franklin D Roosevelt, died suddenly in April 1945. But Truman’s presidency, in retrospect, came to be viewed as one of great consequence.

Despite low expectations for the failed haberdasher from Missouri, Truman ended World War 2 by dropping the atom bomb, contained the Soviet Union and went to war in Korea as the Cold War started.

Senator Adlai Stevenson of Illinois wrote that Truman provided a singular lesson: an example of “the ability of this society to yield up, from the most unremarkable origins, the most remarkable men”.

“Some among us” – a favoured phrase of Thabo Mbeki – held some hope that President Jacob Zuma might become the Truman of South Africa – a warm personality, connection to his roots, common sense in his approach to policy and a consultative manner all suggested a step change from the icy disdain of his predecessor.

Indeed, the first swing away from the previous decade happened early on Zuma’s watch. Sweeping away the denialism that ruinously characterised the inherited policy on HIV/Aids, Zuma appointed a sensible minister of health. He allowed immunology and science, not superstition and quackery, to set policy. The results were impressive and drew admiration from the world.

His initial appointments to key offices, from Reserve Bank governor Gill Marcus to Public Protector Thuli Madonsela, suggested that independence of spirit and competence would be championed.

Some would think that the parallel between the early Zuma and the post-presidential glow that history conferred on Truman is absurdly exaggerated. After all, Zuma barely escaped hundreds of corruption charges and his supporters flattened judicial instruments designed to interdict high-level criminality as he ascended to the presidency.

Still, back in 1952, vice-presidential candidate Richard Nixon, of all people, assailed Truman for being both “corrupt” and “a traitor”.

Although it would be Nixon who would have to resign office in disgrace, this assumption was fairly widely held at the time.

The actual prowess of Truman’s decisiveness and character is summarised by a slogan he placed on his desk in the Oval Office that could easily be a Tweet : “The buck stops here”.

In word and deed, Truman signalled that not only was he in charge of making the tough calls, he took responsibility for them, too.

But how far politics and leadership has fallen since Truman is, alas, fairly universal.

Before announcing another run for the White House, Hillary Clinton gave a strangulated explanation for deleting thousands of e-mails from her computer when she was secretary of state. An unimpressed editor, David Remnick of The New Yorker, archly noted: “It’s one thing for a politician to be stupid; it is quite another for her to assume we are.”

The presumption of stupidity and denialism are alive in South Africa, at a time of converging crises. Our leaders do not shoulder the blame for things that go wrong, or discard obviously failed policies.

Towering above us is King Goodwill Zwelithini. His words are widely believed to have lit the embers of resentment against “the others” among us and fired up the murderous assaults on foreigners.

His imbizo on Monday was a belated call for tolerance, but he then pointed the finger of blame at an unnamed “third force”.

Sunday Times photographer James Oatway’s searing front-page photograph of the murder of Emmanuel Sithole in Alexandra, Johannesburg, shamed our nation and jolted it into action.

However, Zuma bemoaned the lack of a “patriotic media” and said the photographs “made South Africa look bad internationally”.

Eerily, this is an uncomfortable update of a famous exchange Helen Suzman once recounted during the height of apartheid.

After asking a raft of difficult questions on the gamut of the suppression of the rule of law, she noted: “So infuriated was one cabinet minister that he shouted in parliament: ‘You put these questions just to embarrass South Africa overseas.’ I replied: ‘It is not my questions that embarrass South Africa – it is your answers.'”

Zuma, sometimes correctly and sometimes not, blames apartheid for our misfortunes. He should rather acknowledge where the buck stops.