Hmmm. Is it in the registry?
this would end if the mods close all obsolete or run-out poll-threads. you could easily see when a poll is finished and which ones are active. also, maybe people then tend to discuss things outside the poll-threads ;-)
proposal:
mods close the poll-thread as soon as the poll finished(!). if they see heavy discussion, they open a discussion thread in the citizen forum and put a link to that discussion thread into their close message to maintain this discussion.
they also remove the link in the poll-registry then.