Imagine a ruling political party whose leader has become both a national and an international embarrassment.
He is mired in corruption allegations, involving nepotism, influence-peddling, and conflicts of interest. His administration is woefully ineffective, and his country suffers from eye-wateringly high levels of violence.
He has also been accused of serious sexual misbehaviour going back over several years.
If you're thinking Donald Trump, think again. Because I'm thinking Jacob Zuma -- and how his party, South Africa's long dominant African National Congress, forced him to resign as president. The comparison should shame every single Republican member of the US Congress.
The first thing that needs to be said is that -- unlike Robert Mugabe's comrades in neighbouring Zimbabwe -- the ANC did everything exactly by the book. Admittedly, they took their time about it -- Zuma's unfitness for the presidency was evident even before he took office, but the fact remains that when it came to the crunch, there were no tanks on the streets, just a series of votes by party members in meticulous accordance with the rules.
And the second thing that needs to be said is that -- even though the ANC is hardly a byword for good governance and transparency -- it surely deserves at least two cheers for the way it has handled the crisis.
It is true that for far too long, too many senior ANC figures were prepared to turn a blind eye to blatant corruption so long as they were among the beneficiaries. But the party did belatedly recognise that its leader was doing immense harm to both his party and his country -- so with courage and determination it did what had to be done. That it could -- should -- have acted sooner is beyond doubt, but eventually it did act.
Unlike, it has to be said, the Republicans in the US, who have shown neither courage nor determination but have preferred to sit on their hands with their eyes shut, even though they know that their president is likely to drag them towards disaster -- to say nothing of what he's doing to their country.
Given what Mr Trump thinks of countries he likes to refer to as 'shitholes', he is unlikely to relish the notion that South Africa has anything to teach the US in how to manage its affairs. And I certainly wouldn't go so far as to describe the ANC as a model of democratic propriety. Its record is not exactly unblemished.
But credit where credit is due. When they finally decided that it was time for Zuma to go, they got on with it. They elected a successor (not his ex-wife, which was his preferred option), and embarked on an impressively-managed transition. (I wonder, incidentally, how many British Conservatives have been enviously following the process. If only they could manage something similar ...)
So I say again: shame on US Republicans for wilfully failing to halt what the New York Times columnist Nicholas Kristof calls the 'contagion of dishonour' that is spreading through the White House, characterised by 'a lack of integrity, an absence of a moral compass, a narcissism in which the all-consuming need becomes to protect oneself and one’s boss.'
Mind you, the new South African president, Cyril Ramaphosa, will have his work cut out. (There is an excellent profile of him, published in 2013, here.) He is a man of immense experience and substantial achievements, both as a trade unionist and, more recently, as a businessman who has amassed a fortune estimated last year to be worth more than 550 million US dollars.
Both his party and his country are in a sorry state. In the twenty-four years since the ANC came to power in South Africa's first post-apartheid elections, it has largely squandered its reputation as the nation's liberation movement. The Mandela glow has long gone, with both Thabo Mbeki and Jacob Zuma having been exposed as sadly inadequate for the task with which they had been entrusted.
Ramaphosa was originally Mandela's preferred successor -- he was the ANC's lead negotiator in the talks that ended apartheid -- and he now has to find a way to satisfy the expectations not only of international investors but, just as importantly, of an understandably impatient and disillusioned electorate, far too many of whom have seen precious little improvement in their living conditions since the end of apartheid in 1994.
Among the first challenges that he will face will be the future of Jacob Zuma himself, because unlike Robert Mugabe, the ex-president does not appear to have been promised any immunity from the threat of criminal prosecution for corruption.
For all its problems, principally a stagnant economy and unsustainable levels of social and economic inequality, South Africa still boasts a largely independent judiciary, a vibrant free press, and a tradition of civil society engagement, all of which have served it well.
But it also has one of the highest crime rates in the world, with a murder rate nearly seven times higher than that of the US (thirty-four murders per 100,000 population, compared to fewer than five per 100,000).
Mr Ramaphosa will undoubtedly disappoint the millions of South Africans who will be looking to him for a better future. But however far he falls short of their hopes, he will be better than Jacob Zuma.
Just as whoever -- eventually-- follows Donald Trump can only be better, both for the US and for the rest of the world. So wouldn't it be wonderful if the US Congress would ponder on the lessons to be learned from South Africa.
And of course it would be beyond wonderful if they would also ponder the four hundred people -- four hundred! -- who have been shot in US schools since the Sandy Hook mass shooting in December 2012, seventeen of them killed on Wednesday alone at the Marjory Stoneman Douglas High School in Parkland, Florida.
Another medal of shame for the US Congress.