"What it says is that we are still deeply divided. The power of that alternative worldview that's presented in the media that those voters consume -- it carries a lot of weight," Obama told CBS News' Gayle King in an interview that aired on "CBS Sunday Morning."

Asked by King if that worries him, the former President responded, "Yes. It's very hard for our democracy to function if we are operating on just completely different sets of facts."

Obama has done a series of interviews timed to the release of the first volume of his memoir, "A Promised Land," which will be available November 17. The book chronicles the 44th President's childhood and political rise, before diving into his historic 2008 campaign and first four years in the White House.

Obama, the country's first Black president, also confronts the racist politics of President Donald Trump, suggesting his 2008 election opened a wave of bitter and divisive turmoil that fueled Republicans' obstructionism and ultimately changed the party.

Obama on Sunday defended his active campaigning for President-elect Joe Biden, his former vice president, saying circumstances warranted his public criticism of his successor -- something that former presidents usually don't do.

"It is not my preference to be out there," he told King. "I think we were in a circumstance in this election in which certain norms, certain institutional values that are so extraordinarily important, had been breached. That it was important for me, as somebody who had served in that office, to simply let people know, 'This is not normal.'"

Trump has refused to concede, repeatedly claiming without evidence that the election was rigged and continuing to push unsupported legal challenges of the results. The formal transition between the Trump administration and the incoming Biden-Harris administration is likely to remain on hold until the election is certified by a Trump appointee within the General Services Administration in a process known as ascertainment.

During a separate interview with CBS' Scott Pelley that is set to air Sunday on "60 Minutes," Obama slammed Republican officials for backing the President's false claims of election fraud and said the allegations endangered democracy. And speaking on the importance of a peaceful transition with King, Obama said that "it's a temporary job. We're not above the rules. We're not above the law. That's the essence of our democracy."

Asked what advice he would give Biden, Obama said he believes the President-elect doesn't need his advice but pledged to help him in "any ways that I can."

"I'm not planning to suddenly work on the White House staff or something ... Michelle would leave me," he joked of the former first lady. "She'd be like what?

You're doing what?"

Although, Trump has frequently attacked Obama, the former President said he does not take them seriously.

"There are many things he says that I do not take personally or seriously, although I think they can often be destructive and harmful," Obama told King.