Fox News anchor Bill O'Reilly dropped by "The Late Show" on Monday night where he explained to host Stephen Colbert his theory that Democratic presidential candidate Bernie Sanders and GOP presidential candidate Donald Trump were actually the same person.

"They just change their facial expressions," O'Reilly said of Trump and Sanders.

"I've never seen them in the same room at the same time," Colbert said.

"Trump and Sanders are the same guy, because both are tapping into anger, the anger of the voters, who feels they're getting hosed," the conservative heavyweight told Colbert. "On the right, they don't like the fact that there is an open border and they can't solve that problem of ISIS beheading Americans, just anger. On the left, they feel that the economy is run by the billionaires."

"The billionaires," O'Reilly said as he tried to impersonate Sanders, "and I am going to solve it. It's rigged!"

"I'm sorry, did you just have a stroke just now? I don't understand what you're doing," Colbert said of O'Reilly impression of Sanders.

O'Relly then told "The Late Show" host that the American people want an "avenger" this time around and not a politician, a quality he said people see in Trump and Sanders. The host of "The O'Reilly Factor" then explained the good and bad of both candidates' campaigns.

"The good part about it is that it gets everyone engaged in the political process," O'Reilly said. "Trump himself has performed a miracle in making Americans actually pay attention to what's happening, so that's good. What's bad is that Trump and Sanders say stuff that's impossible, it could never happen."

Check out Colbert's interview with O'Reilly below: