[postultimate]

Welp, HN has nerdsniped me again: After some unpaid pondering, here's my suggestion for a middle ground on downvoting:

1) Reduce issue-related downvoting by only allowing some random subset of the current active users to downvote, a different set per post. Don't let the user know their vote won't work in advance, but tell them after.

2) Reduce vote sockpuppeting by recording which pairs of voters downvoted a post, then disallow that pair from downvoting a post again. This includes votes that failed due to 1).