Washington Post columnist Philip Bump owned former Trump spokesperson Marc Lotter in a curt fact-check exchange Thursday on CNN. (Watch the videos below.)

Lotter pivoted from commenting about Kamala Harris’ campaign outing with Liz Cheney, a Republican, to claim that “Harris let in 13,000 murderers who are illegal immigrants in our country.”

“All of these things are very real,” he continued in echoing falsehoods asserted by Trump.

Host Erin Burnett attempted to engage Bump with a question about Harris stumping in heavily Republican regions. But the reporter wasn’t about to ignore the comments of Lotter, the strategic communications director for Trump’s 2020 campaign.

“Yeah, I just want to say, first of all, what Mr. Lotter just said about the 13,000 immigrants is absolutely false,” Bump said. “And I think it’s important to point that out.”

“It came from ICE, Phil,” Lotter shot back, referencing Immigration and Customs Enforcement, a federal agency tasked with border security. “Be a reporter.”

Bump dug in further. “It’s not true. It’s absolutely not true.”

“Those were people that were in the country for decades,” Bump continued. “Many of them are in custody currently because they were charged with murders. I’ve actually done the reporting on this. So you can trust me, viewers.”

“Democracy dies in darkness, Phil,” Lotter wisecracked.

“That’s right. That’s right,” Bump retorted. “That’s why we’re honest with our viewers and with our readers.”

So there!

In fact, The Washington Post on Thursday conducted an extensive debunking of Trump’s claim, calling it a “figment of his imagination” on top of Bump’s previous work on how the data has been misrepresented.

The two men continued their argument on social media.