A few months ago, the ability to remove polls after being accepted, was removed.
I and several other users (including non-admins who make a mistake and want to fix it) would really like this to come back, or at least the ability to edit them, with admin approval + comparison to the old version of the poll.
Users can't even delete their own polls, and as far as I know, it's the only user content on the site that cannot be removed, even by its creator.
By 
By 