What quorum of the membership do you suggest?
You can't use the membership as a starting point for anything. There are thousands upon thousands of members, and only a few hundred show up within a given period of time.
Besides, if I wanted to recommend a course of action to the moderators, I would put together a PM and let them all know what I had in mind. The poll would be fer funsies. I bet that if it had been left up the voting would have been in favor of banning him.
But you can't take such a poll seriously because it only represents the people who cared enough to vote. It wouldn't speak to the wants and needs of the membership as a whole.
But those around here who like to use plausible looking statistics to lie, and there are many of them, could have a field day with such a thing.