In last night's New Hampshire U.S. Senate debate, moderator Chuck Todd asked Republican Scott Brown to expand on his argument that ISIS could cross the Mexican border to attack America. What happened next was a little surprising to anyone who'd paid even fitful attention to the race.

TODD: Senator Brown, you have suggested that the Islamic militant group ISIS could come across the U.S. border, in fact, saying that is, quote, “the most obvious pathway for terrorists to enter our country.” What is the evidence for that assertion? We've had terrorists come across the border, the north of the border. 

BROWN: With respect, I did not say that. What I have said is that ISIS is real. 

He did say that, and he wanted the press to hear him say it. In a heavily promoted foreign policy speech last month, Brown warned voters that “these ISIS thugs have been saying for months that they’re going to send people here to kill Americans on as big a scale as they can, and never mind that a porous border is the most obvious pathway for terrorists to enter our country.”

Fine, sure: To be fair to Brown, he didn't just suggest that ISIS could cross the border. He suggested that the Islamic State might have figured this out already. “There's deep concerns that there are members of ISIS actually coming through the border right now,” Brown said on Fox News after he locked up his Senate nomination. “We need to secure the border, once and for all.”

That seemed to work for him — stubbornly behind in polls, he got a little closer in the weeks after airstrikes began hitting ISIS — and when the Ebola scare hit, Brown added it to the litany of Rio Grande dangers. “I think it’s naive to think that people aren’t going to be walking through here who have those types of diseases and/or other types of intent, criminal or terrorist,” he told WGIR Radio last week.

What could possibly explain Brown's glaring, live-in-front-of-a-studio-audience whopper? He had a better handle on the ISIS scare before he started on the border angle; he was an early promoter, for example, of ripping American citizenship away from anyone who joined ISIS. Then the border focus seemingly caught fire with voters, and Brown scrambled out onto a series of thinner and flimsier limbs, until Chuck Todd noticed and Brown attempted to argue that there was no limb. This answer belongs in the “with all respect/all due respect” hall of fame.

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