When former New York governor George Pataki was asked during the CNN undercard debate about Donald Trump's remark that Bowe Bergdahl should be executed, Sen. Lindsey Graham could be heard laughing off-camera.

When he got the chance to address the issue. Graham was direct. "Mr. Trump, you don't have to speak about everything," he said, looking into the camera. "It's not required."

That curt dismissal of the guy polling 38 times better than him came after an hour-plus of Graham having dominated everyone who was in the room with him. In a debate focused on foreign policy, Graham came off as the only one who had confidence in what he was saying. The other candidates used him as sounding board as much as they offered their own ideas; the moderators used him as a temperature check.

In part that's because of Graham's military service and history of active participation in foreign policy issues. But it's also because he was the most spirited person on stage. Whether Graham came prepared with all of the one-liners or whether they were purely off the cuff, he had some doozies.

"I'm not afraid of a guy riding around on a horse without a shirt," he said of Russian president Vladimir Putin. The Islamic State would be dancing in the street at Trump's comments, he said, except that the Islamic State prohibits dancing. "Princess Buttercup would not like this!," he yelped, criticizing Ted Cruz by way of a character in his favorite movie, "The Princess Bride." "As to women [in the military]? If you want to kill terrorists," he assured the bellicose ladies in the audience, "I'm your man."

Simply put, Graham was in a different league. We use Google search data as a way of checking interest in the candidates in real time -- and no one generated as much interest as the senator from South Carolina. It peaked when he was talking about his military experience.

CNN used new, expanded criteria to determine who made the main debate stage this time (to Rand Paul's benefit). But Graham's dominance -- and, in particular, his critiques of the front-runner -- demonstrated that the criteria are silly.

Graham should be in the main debate. Not only for the entertainment value (but admittedly in part for the entertainment value), but because he has a different perspective than a lot of the other candidates.

Including Trump. Graham and Trump differ on issues, but Graham also seems to have a sense for Trump's Achilles heel. The tycoon's only demonstrated weakness against his opponents is when he's the butt of someone else's zinger -- which we saw in the second debate after Carly Fiorina put him in his place. So far, the only significant on-going challenge to Trump in the debates has been questions he didn't want to answer. He can't be used to dealing with people who are able to spar as well as he can. Wouldn't that be fun to watch?

At some point, the debates will abandon the undercard debate format, as the pool of candidates thins or simply for the sake of expediency. We've had five debates now in which Graham has performed exceptionally in the undercard debate and various cold fish flopped around during the main event.

Graham's poll numbers haven't warranted an invitation to the big leagues. His performances have.