IMO he just used a bad choice of words.
Thousands were killed by those terrorists. Building that on that site is like a blow to those that lost their lives. And to their families.
It could easily be built some where else.
As an American, I don't want anything there that will only aggravate the situation further.
They have mosques here to worship in. What would happen if we went and built a Baptist church, as an example, over there on ground they chose to honor their dead?
As for the clip, I agree with Barbara Waltera there. There should be no reason why they had to walk off, just sit there and debate.
But, the whole 9/11 Mosque controversy didn't sit well with me at all. The Mosque wasn't going to be built on any kinda of hallowed ground. It was not on any kind of land that the people died. As somone pointed out, it was in the surrounding area (a couple blocks away) from the empty site, just like a strip club was in the surrounding area. They can go ahead and build it there and I don't really care. As for us building something over there, well, aren't we supposed to be better than them?