MC Banhammer on that other thread Posted:

What about a second screen on which you’d see votes below the -5 threshold which you haven’t voted on? On that screen it would only allow for upvoting and pbum. This would allow good suggestions which have been griefed a chance to get back up from the people who actually care about the quality of submission.

Barring the outright removal of downvoting, this might actually be the best approach to handling gratuitous downvoting. This way, content that has been downvoted for no good reason – that might just be good – may have a chance to move back up into the running. Any other ideas?