Jon Stewart shot himself in the foot on Monday’s “Daily Show” when he interviewed Bob Costas about the gun control comments the sportscaster had made during a football game, landing Costas in hot water last month.

During Costas’s appearance on the Comedy Central show — whose advertisers include violent films — Stewart wondered what it was like to be at the epicenter of the gun control argument.

Costas set off a firestorm during his halftime slot of an NBC Sunday football broadcast in early December when he discussed the previous day’s suicide of Jovan Belcher; the Kansas City Chiefs linebacker shot himself Dec. 1 after killing the mother of his baby daughter, using his legally registered gun.

Among other comments last month, Costas read from a column by Fox Sports columnist Jason Whitlock: “If Jovan Belcher didn’t possess a gun, he and Kasandra Perkins would both be alive today.” Much hoo-ha followed, in which some industry navel-lint pickers debated whether NBC should sack Costas.

Costas told Stewart that he’d been let off the hook when “Newtown happened.” He added that the slaughter of 20 elementary school children and six adults, “as horribly tragic as that was, if it did redirect the debate — and people are now at least somewhat more willing to think about this rationally and compassionately — then that is a good thing.”

Chris Cuomo will anchor a new morning show on CNN. (Ida Mae Astute/ABC)

While we contemplated how many ways Costas could have put that less chillingly, Costas continued his blah, blah, blah.

“How do we change the culture then?” Stewart asked, earnestly. “Is it that guns look cool? Is it real self-protection? Is it real Second Amendment rights?

“Or is the idea, ‘I’ve seen enough movies to know if I go in some place and do this’?” Stewart asked, making a gun-in-hand hipster gesture.

This is a slippery slope for Stewart, given that any discussion of gun culture invariably touches on violent movies and videogames and that his show is one of advertisers’ fave places to promote those products because it attracts a high concentration of young male viewers.

And sure enough, Costas went there: “Right now, everywhere you look there is a commercial for a . . . Sly Stallone movie called ‘Bullet to the Head,’ ” Costas responded.

That was awkward because, immediately before Costas came onstage to chat with Stewart, “The Daily Show” ran a “Bullet to the Head” ad.

“Bullet to the Head,” as its title suggests, stars Stallone as a hitman who teams with a young Washington detective after they’re brought together by two vicious murders; together they exact Revenge.

It was the show’s second ad break. The first one featured a commercial for another guys-with-big-guns flick: “A Good Day to Die Hard,” in which Bruce Willis reprises his John McClane role — this time traveling to Russia to get his son out of the slammer, only to become caught up in a terrorist plot.

(The third and final ad break featured a plug for yet another guys-with-big-guns flick, “Snitch.” Dwayne “The Rock” Johnson plays a dad who cuts a deal with the U.S. attorney’s office to infiltrate a drug cartel after his son is wrongfully arrested for distributing drugs and sentenced to 10 years in the hoosegow — though we had no way of knowing that while Costas was prattling away about “Bullet to the Head.”)

Anyway, the reference to a media landscape littered with “Bullet to the Head” ads seemed to make Stewart uncomfortable. Or maybe we’re giving him too much credit.

“That’s a working title,” Stewart began to joke/soft-shoe, adding: “Once you’ve thrown Mama from the train, what difference does it make.”

Costas chuckled. “There are many aspects to this,” he acknowledged.

The moment was gone.

Cuomo to CNN

Less than two weeks after officially taking the reins at CNN, Jeff Zucker announced that ABC “20/20” co-anchor Chris Cuomo had come on board to host a new morning show for the ratings-starved cable news network.

In other Zucker-shaking-CNN-till-its-teeth-rattle news: Network contributor James Carville made the press rounds Tuesday, putting his spin on his and wife Mary Matalin’s exit from the network; CNN Exec VP/Managing Editor Mark Whitaker sent an e-mail to staff Tuesday morning to announce his own bow out; and contributor Erik Erickson put out word that he’s out, too, and that his 7-year-old daughter is prostrate with grief at the thought of never meeting Anderson Cooper.

Busy day all around at CNN.

“Chris is an accomplished anchor who is already an established name in morning television, as well as a widely respected investigative journalist,” Zucker, the CNN worldwide prez, said of his latest hire. “What I love about Chris is that he is passionate about every story he tells, never forgets about the viewer and represents the type of journalism that makes CNN great.”

Cuomo was ABC’s “Good Morning America” news anchor from 2006 to 2009. Zucker, meanwhile, is the guy who exec-produced NBC’s “Today” during the Katie Couric glory years.

Not long after Zucker made Cuomo’s defection official, ABC News President Ben Sherwood announced that correspondent David Muir had replaced Cuomo on “20/20,” joining Elizabeth Vargas. In that announcement, Sherwood spoke glowingly of both men, concluding, “Please join me in thanking Chris and congratulating David.”

To read previous columns by Lisa de Moraes, go to