"We managed to keep this civilised!" declares Vince Conti, moments after a complete stranger has called him a bigot. "I am so upset," growls his opponent Yasser Aggour. "This is latent bigotry exploding."
The two men – one Roman Catholic the other Muslim – have collided outside the abandoned Burlington Coat Factory discount store on Park Place in Lower Manhattan which is slated to be converted into a Muslim community centre and mosque. They are navigating the same quandary that has gripped the whole country and consumed national political discourse. Should a mosque open here so close to the site of the 9/11 attacks?
"I am not anti-Islam," insists Mr Conti, 52, who perhaps went a bit far by suggesting that he would respect Mr Aggour more if he would just "turn in" his Muslim brothers he knows to be terrorists. "But why can't they move it to a different location? This is such a sensitive place." He gestures towards Ground Zero, where American flags flutter from cranes that have come to rest for the night.
Mr Conti suggests that, if he cannot bring himself to accept that the new centre should be in this block, it may be because he witnessed the attacks at first hand. He still works in the World Financial Centre adjacent to Ground Zero. "I saw the terror. I saw the people jumping."
He presses on: "The people who will be coming here to this centre will be saying the same prayers that the terrorists prayed when they attacked and they will be saying them with the same exuberance and the same passion as the terrorists. It will be ringing out all the way to Ground Zero. I'm bothered by that."
On this night, however, Mr Conti finds himself in something of a minority. Handing out flyers to a strip club just around the corner, a young man originally from Morocco, who calls himself Jay, scoffs at the opponents to the mosque. "This country is a melting pot. If they build it right here it actually would be a good thing. People against it are just not open-minded. I think they have been brainwashed."
At the coat factory, Bryan Gillis is one of several young New Yorkers who have gathered with placards supporting the rights of Muslims to open a place of worship here.
"Bin Laden wants US to think that Islam and al-Qa'ida are the same," his makeshift sign says. "Let us show them we beg to differ."
Matt Sky and his girlfriend Julia Lundy have spent the past three days outside the old coat store waving similar placards at anyone who will take notice demanding that America live up to its promise of tolerance and openness. The reaction has not always been friendly. "We've been called terrorists; we had a bucket thrown at us, cigarette stubs ... Someone even grabbed the placards and threw them under a truck," Mr Sky, 26, reports with undiminished enthusiasm. He adds: "I think we have even been able to change a few people's minds." .........
Walk two blocks from here and – if you look really hard – you will find the scruffy, single-basement mosque that already serves Muslims in this area. The tiny Masjid of Lower Manhattan was founded in 1970 and moved to its current address on Warren Street two years ago.
Farid Baig, 40, a limousine driver, stops his car here twice a day to pray. He came to America 10 years ago from Pakistan and confesses to profound disappointment that plans for the bigger mosque have met so much opposition. "This will be a place of God and a place of peace," he says. "Not everyone is a terrorist because they are a Muslim."