On CBS' Face the Nation, Republican presidential frontrunner Donald Trump promoted the bogus theory that the wives and families of the 9/11 hijackers “absolutely knew what was happening” and were flown “back to Saudi Arabia” days before the attack as part of his call for extra scrutiny and surveillance of Muslim communities in the United States.

On November 21, Trump falsely claimed that he watched “thousands and thousands” of Muslims in Jersey City, New Jersey cheering the destruction of the World Trade Center on September 11, 2001. The remark was rated as a "Pants on Fire!" lie by PolitiFact multiple times, but right-wing media rallied around Trump's misinformation. In the wake of the deadly December 2 mass shooting in San Bernardino, California that left 14 people dead and many more injured, several Republican politicians and conservative outlets have advocated increased profiling of Muslims living in the United States. On the December 6 edition of CBS' Face the Nation, Trump called for increased surveillance of Muslim families in the U.S., suggested that the family of the San Bernardino shooters was lying about not having forewarning of the attack, and was allowed to push his conspiracy theory about the 9/11 hijackers unabated, despite that fact that it has been known for many years that all but one of the hijackers were unmarried:

JOHN DICKERSON (HOST): You mentioned political correctness about Muslims. What the criticism of you is, that you are playing on fears that people have, and you're stoking them. 

DONALD TRUMP: No, I'm playing on common sense. No, no I'm not playing on fears, I don't want to play on fears, I understand the whole world, and I understand. And I have Muslim friends who are great people, and by the way, they tell me there's a big problem. I'm not playing on fears, I'm playing on common sense. We have a problem. The World Trade Center came down, and by the way speaking of coming down, they put their families on airplanes, couple of days before, sent them back to Saudi Arabia for the most part. Those wives knew exactly what was going to happen. And those wives went home to watch their husbands knock down the World Trade Center, the Pentagon, and wherever the third plane was going, except we had some very, very brave passengers, wherever that third plane was going. Those wives knew exactly what was happening.

DICKERSON: You mention the families, going after the families, what does that mean? How would that work?

TRUMP: Well, at least I would certainly go after the wives, who absolutely knew what was happening, and I guess your definition of what I do, I'm going to leave that to your imagination. But, I will tell you I would be very tough on families, because the families know what is happening. Even in this last instance, I see everybody knew, so many people knew, they thought that this man and this woman, you know whether he was radicalized or how he became, they thought something was going on. Why don't these people report it to the police? Why wouldn't they report it to the police? Now, they said it was profiling. They didn't want to profile. Can you believe this? They didn't want to profile, even though they thought something very bad was going to happen.

DICKERSON: His sister said she didn't know what was going on, she was crestfallen for the victims here.

TRUMP: I probably don't believe the sister.

DICKERSON: You don't believe the sister, so you would go after her?

TRUMP: I would go after a lot of people, and find out whether or not they knew. I'd be able to find out, because I don't believe the sister.

Media Matters researcher Brendan Karet contributed to this blog