If he was seriously trying to change this guy's mind, going the 'It's not in the constitution' or that it's 'unconstitutional' is not the way to go, because to anyone who believes in big government - 'liberal' or 'conservative' - if the constitution says something that stops them from doing what they want, they WILL start treating it like just a piece of paper no matter all those sympathetic noises they made toward the 1st and 4th amendments.
They'd have to give a damn about the constitution, first. If anything directly contradicts them in that document, they will write it up to having been drawn up by a bunch of backwards savages.
And he keeps harping on about 'You are a republican', 'We aren't in the same party'. This guy is Blue Team all the way and will simply regurgitate everything he hears from the rest of the Team. The only amount of thought he's put into what he thinks about OWS is color recognition.