The ghost of US presidents past made an appearance in South Africa.

Barack Obama offered what some of his supporters will see as not-so-veiled references to his successor in a speech honouring Nelson Mandela’s legacy, defending democratic institutions and a free press, and condemning “strongman politics” and shameless leaders who “double down” when caught in lies.

The former president also offered a commodity he always seems to have in ready supply – hope.

“Things may go backwards for a while, but – ultimately – right makes might,” Mr Obama said. “Not the other way around.”

It’s a riff on the Theodore Parker line he frequently quotes, about the arc of history being long, but bending toward justice.

If Mr Obama had a message for the world – and particularly for Americans unsure about course their nation is on – it’s that the struggle is real, but the ending is a happy one.

There are probably more than a few on the left, however, who wish Mr Obama would give more than a few speeches and carefully worded statements.

With mid-term elections that will determine control of Congress just four months away, they want him to step away from the podium and fully join the fight.

“Just as people spoke about the triumph of democracy in the 90s, now people are talking about the end of democracy,” says Mr Obama.

“We have to resist that cynicism. Because, we’ve been through darker times, we’ve been in lower valleys.”

Mandela’s story teaches us that we need to remain hopeful, he says.

“That journey [of Mr Mandela] was not easy. It was not preordained. The man went to prison for almost three decades.”

And yet, Mr Obama says, his power actually grew while he was in jail.

“He knew if he stuck to what he knew was true… then it might not happen tomorrow, it might not happen next week, it might not even happen in your lifetime, but ultimately the better story can win out.”

He says young people need to be “fired up”.

“We don’t just need one leader… what we badly need is that collective spirit,” he says.

“So young people, my message to you is simple: keep believing, keep marching, keep raising your voice.”

“You have to believe in facts,” he tells the crowd. “Without facts there is no basis for cooperation.

“If I say this is a podium and you say this is an elephant, it is going to be hard for us to cooperate.”

He adds he can find common ground with people who disagree with the Paris accord – which Donald Trump wants to pull the US out of – if they have an argument based in facts.

But, he adds: “I can’t find common ground if someone says climate change is not happening when almost all the world’s scientists say it is. If you start saying it is an elaborate hoax, where do we start?”

Mr Trump has said he thinks climate change is not happening.

As an aside a moment later, Mr Obama turns to the politicians of today.

“It used to be if you caught them lying, they said, oh man. Now they just keep on lying.”

 

Source: BBC