"I am not being alarmist, I am simply stating the facts", he said.
And, people in other countries have expressed decreased confidence in America's leadership in global affairs since Obama left the White House, according to 2017 Pew center survey. It said it obtained them after years of litigation. Without facts there is no basis for co-operation.
"I can find common ground for those who oppose the Paris Accords". Just as people spoke about the triumph of democracy in the '90s, now you're hearing people talk about the end of democracy and the triumph of tribalism and the strong man. "If you start saying it's an elaborate hoax, where do we start?"
Obama pivoted to specific issues like the immigration crisis boiling over at the U.S. - Mexico border and Trump's gleeful shredding of objective truth in favor of political expediency.
"People just make stuff up. Now they just keep on lying". "Should we see that hope that we had as naive and misguided?" he asked.
In his speech Wednesday, Obama also denounced political leaders for lying. Every generation has opportunity to remake the world...
The former US president suggested a different path."Let me tell you what I believe", he said.
"Social media, once seen as a mechanism to promote knowledge and understanding and solidarity, has proved to be just as effective promoting hatred and paranoia and propaganda and conspiracy theories", he added.
The crowd greeted him by enthusiastically chanting "Yes, we can" - an echo of Mr. Obama's famous election slogan.
"(He) shows those of us who believe in freedom and democracy we are going to have to fight harder".More news: Manny Machado Trade 'Very Close'
Thousands of pages of USA intelligence documents on Nelson Mandela were made public on Wednesday, revealing that Washington continued to monitor the South African anti-apartheid hero as a potential Communist menace even after he was released from prison, a group that sued to obtain the papers said. From the Berlin Wall coming down?
He said: "I believe in Nelson Mandela's vision" for the world's future, I believe that a world governed by such principals is possible.
After 27 years in prison in South Africa, Mandela was released in 1990 and became the country's first black president four years later.
"Racial discrimination still exists in the United States and South Africa".
"From the humblest of beginnings, they are representatives of the masses and reached to the pinnacle of power and influence".
"That kind of co-operation we should be able to do right now".
Both he and Obama were the first black presidents of their countries.
The leaders were hosted by Nelson Mandela's grandson Chief Zwelivelile Mandela at the anti-apartheid icon's rural home in Mveso in Eastern Cape, South Africa. He died in 2013 at the age of 95.
It was the second major speech from Obama in South Africa in two days after a previous stop-off in Kenya.
Laura Ingraham criticized former President Barack Obama for attempting to "breathe life into his sad legacy" with his address in South Africa.