His comments came in a taped interview set to air on "Fox News Sunday".
Throughout his speech, Obama placed emphasis on the upcoming midterm elections, urging the young attendees to shake away any ideas that would deter them from the voting this November.
Republican officials said Sunday it was disappointing to see both President Obama break the past example of recent ex-presidents by re-entering the political scene last week with a stinging rebuke of his successor, and for Mr. Obama to try to take credit for a burgeoning economy under President Trump.
"Your version of America is not the America we want", Pirro said on Saturday night in a message to Obama.
President Obama is expected to deliver a similar message in Cleveland on Thursday, when he campaigns on behalf of Richard Cordray, the Democratic nominee for OH governor, and other Democrats. "You, Barack. You elected Donald Trump". To that end, he named seven California Democrats, offering them brief and enthusiastic endorsements that were captured on Democratic Party cameras and that will presumably end up in candidate advertisements before long.
Noting the history of former presidents avoiding the rough and tumble of politics, Obama acknowledged that his sharp critique of Trump was something of a departure from tradition.
"The biggest threat to our democracy.is not one individual, it is not one big super PAC of billionaires", Obama said.
"I think we've gotten to a point where we just are completely unable to support the president, no matter who the president is", former New York Governor David Paterson told radio host John Catsimatidis on AM 970 in New York. "People feel unsettled, people feel scared", he added. That's how real change starts, Obama said.
He also warned of the temptation for politicians to divide people and find "scapegoats" for their own power and gain.
When that happens, he says, people become cynical and decide not to participate in the political process - creating a vacuum that lobbyists and special interests fill.
On Saturday, the former president will stump for House Democratic candidates from California at an event in Orange County, a conservative-leaning part of California where Republicans are at risk of losing several congressional seats.
Then president Barack Obama and first lady Michelle Obama pose with then president-elect Donald Trump and his wife Melania at the White House in Washington, Friday, Jan. 20, 2017.