Former U.S. President Barack Obama on September 20, 2017 in New York City.

Americans are living in a political "bubble" by personalizing their respective media streams, according to former President Barack Obama.

People who watch Fox News are "living on a different planet" than individuals who listen to National Public Radio, the 56 year-old told David Letterman in a November interview that was released Friday under the veteran talk show host's new series.

"One of the biggest challenges we have to our democracy is the degree to which we don't share a common baseline of facts," the former leader said. "What the Russians exploited, but it was already here, is we are operating in completely ."

"At a certain point, you just live in a bubble. And that's part of why our politics is so polarized right now. I think it is a solvable problem but it's one we have to spend a lot of time thinking about," he continued.

Many commentators have warned of the , pointing to how news outlets spin events based on their respective ideological slants. That impacts social media, too.

If individuals get all their news off , "it's just reinforcing whatever biases you have, which is the pattern that develops," Obama said.

Obama himself relied on platforms such as Facebook and Twitter for his 2007-2008 presidential race, which he referred to as "the most effective political campaign in modern history." At the time however, his team didn't realize "the degree to which people who are in power, special interests, foreign governments, et cetera can, in fact, manipulate [social networks] and propagandize."

The former leader issued similar opinions in a .