This suggestion has been closed automatically because it did not receive enough votes over an extended period of time. If you wish to see this, please search for an open suggestion and, if you don't find any, post a new one.
Often times members view the poll results to vote with the majority, so, to prevent this from happening, I think an option should be implemented to be able to null the members vote once he has viewed the results.
You could make a user's vote be required before current poll results are shown. Or if you wanted it to be restricted further, have it show a bar filling up or something that indicates when the results will be shown, if the poll has a close date.