"These are not ordinary times, these are risky times", the former president, who since leaving office has avoided direct attacks on Trump, said during a speech at the University of IL. One theme of Obama's speech is how the history of the United States has always been progress and "backlash to progress", and the former President argued the country is now in one of those backlash moments. "How hard can that be, saying that Nazis are bad?" he said.
Trump responded during a campaign rally, saying that he "fell asleep".
"This moment really is different".
He praised America's accomplishments but said there is a darker side to progress when politicians peddle resentment and mistrust to preserve the status quo. "A fear and anger that's rooted in our past but it's also born out of the enormous upheavals that are taking place in your brief lifetimes".
After his predecessor took the unusual step of criticizing him by name in a speech Friday, President Donald Trump shot back with childish attacks and blatant lies.
"In two months we have the chance to restore some semblance of sanity to our politics", Obama said. "That is not a check".
"That is not a check, I'm being serious here". That's not how our democracy's supposed to work.
The only thing they have to do, Obama said, is "show up".
See the full speech (above) or check out some of the highlights as he talks about freedom of the press, embracing nazis, and that infamous New York Times op-ed (below)!
Noting the history of former presidents avoiding the rough and tumble of politics, Obama acknowledged his sharp critique of Trump was something of a departure from tradition.
Obama told students "you can not sit back and wait for a saviour", adding the biggest threat to democracy isn't Mr Trump but "indifference".
Barack Obama delivered a very passionate speech meant to remind the citizens that they need to defend and protect Democracy and that voting is a big part of what they can actively do to achieve that.
But on Friday, Obama offered his most pointed indictment of the political climate that has formed under the watch of Trump and the Republican-controlled Congress.
What happened to the Republican Party?
The former president also applauded the women who have taken a stand in the Me Too movement, and the teens of Parkland, Florida, who are standing up to gun violence and the National Rifle Association.
"If you're exhausted of politicians who offer nothing but thoughts and prayers after a mass shooting, you've got to do what the Parkland kids are doing", Obama said.