1) Set a formal threshold for deletion, maybe 75%.

2) Allow sysops to ignore votes by people who
a) are not regular Wikipedia authors (less than 20 edits)

There seems to be a lot of ballot stuffing, going so far that some people
post to Usenet and ask people in a group to support non-deletion of a
page. We can prevent this by allowing only people with a track record to
participate.

b) have not expressed any opinion beyond "keep" or "delete" and have not
made any edit to the page in question.