Facebook.com/Hardball with Chris Matthews

Jonathan Capehart got more than he bargained for while guest-hosting Friday's edition of The Reid Report, which featured Hardball host Chris Matthews discussing Iraq.

Well, Matthews was supposed to discuss Iraq. He veered for a moment into some less-than-constructive criticism of MSNBC colleague Ezra Klein's "explanatory journalism" website Vox.com. In the clip, below, Capehart reads Matthews an excerpt from a piece analyzing the Iraq crisis that appeared on Vox, trying to ask Matthews to respond to the opinion. Instead, Matthews shuts him down — hard.

"I don't respond to that kind of stuff, okay," he says. "That's not of interest to me…Let me deal with the grown-ups, let me deal with the political people and not getting involved in the blogs and the websites."

Klein, who often appears on MSNBC programming as a contributor or guest host, may consider himself a political person, but looks like he may have to debate that with Matthews next time the two bump into each other in the hallways. Watch the full clip, below. --Sarah Eberspacher