GOP unsure how to respond to Duncan Hunter's allegations

Rep. Duncan Hunter, R-Calif., participates in a news conference.
Rep. Duncan Hunter, R-Calif., participates in a news conference.
It's been a few days since Rep. Duncan Hunter (R-Calif.) told a national television audience that Islamic State militants entered the United States through the Southern border. Everyone from the Department of Homeland Security to the Mexican government to the Texas Department of Public Safety says the far-right congressman has no idea what he's talking about, but the Republican continues to claim he has a secret source that has provided him with information no one else has.
 
Of course, if Hunter is correct, it's an extraordinarily big deal. And if the congressman is brazenly lying about a major national security threat, that's arguably pretty important, too.
 
With that in mind, other Republicans are starting to get questions about Hunter's bizarre allegation. Note, for example, this amazing exchange yesterday between Sen. Rob Portman (R-Ohio), a possible 2016 presidential candidate, and CNN's Alisyn Camerota.

CAMEROTA: Have 10 ISIS fighters already been detained? PORTMAN: I don't know. I saw this morning that Jeh Johnson, Secretary of Homeland Security, said that was not necessarily accurate. But, look, it could happen.

Hmm. I suppose it's possible that all sorts of things "could happen," but that's not really the issue at hand. A U.S. congressman believes ISIS terrorists have already infiltrated the nation, and there's a cover-up underway to hide this explosive information from the American public. Either it's true or Hunter made this up, and "it could happen" isn't an especially satisfying answer from a prominent senator.
 
Camerota, to her credit, followed up, asking Portman if he thinks "it's possible" that ISIS fights have already entered the United States.
 
"I just don't know, Alisyn," Portman said. "I do think this is a question that we ought to get answers from the administration on."
 
First, we've already received answers from the administration on this -- DHS Secretary Jeh Johnson called Hunter's allegations "categorically false." Second, Portman is a member of the Senate Homeland Security Committee, and if Republicans take the Senate, he might even become its chairman. If he has no idea what Hunter is talking about, doesn't that suggest the congressman is telling tall tales?
 
Or more to the point, isn't it at least somewhat likely that Rob Portman knows Hunter's claims are absurd, but he's afraid to trash one of his fellow Republicans?
 
As Rachel noted on the show last night, this bizarre story is getting bigger -- and dumber.