Users with sufficiently high reputation can vote to delete and undelete posts. This is something that we need to do occasionally on PPCG, due to things like answers that don't comply with the specification (the most common delete), and answers that didn't comply with the specification, but now do due to a change in the specification (the most common undelete).
Every now and then I check the pending delete votes (note: requires quite a lot of reputation to view), to see if there are any posts on there that require deletion (ditto undeletion, but deletion is more common). Then I check to see if I agree, and cast my delete vote if I do. Recently, though, I nearly always end up getting told "You have already voted to delete this post"; not only are the votes-to-delete staying unresolved for a long time, but so long that I've forgotten I cast my own!
Certainly, bad posts do get deleted on this site, but there are only really two common ways in which it happens: a) the post gets flagged as VLQ, typically due to an intentional spec noncompliance (which places it into the low quality queue and strongly increases the chance that enough users see it that it'll get the delete votes), or b) a diamond moderator sees the post and deletes it unilaterally. These are both worthy methods, but they don't handle the entirety of the content on the site:
- Method a) is the one you're "meant to use" for bad content at PPCG (most likely because it's the only one that actually works well without unwanted side effects), and is quite effective at clearing up invalid answers when you can use it, but it has a major issue that the VLQ option often just doesn't turn up in the flag box (not even if you downvote the post first). In such cases, low-reputation users can't really do anything (a moderator attention flag would be too drastic, and an NAA flag violates our policy), so they just end up leaving the posts alone. In any case, many (possibly even the majority of) invalid answers can't go via the Low Quality queue because the interface blocks it.
- Method b) works fine when the diamond moderators happen to spot the post, but they can't be everywhere at once, and it doesn't really make much sense to force a relatively routine job, which the community is meant to be doing, up to the highest level. As such, summoning moderators every time there's such a post and it can't be VLQ flagged would be unsustainable (and indeed, this is discouraged in practice, although the current policy as stated in this thread is indeed to use a moderator attention flag unless it seems plausible that the post might actually gather enough "drive-by" deletion votes votes).
Now, the reasoning here concludes that ideally, if it worked, we would be using a third method (indeed, the intended one): three users with enough reputation to cast delete votes do so. The problem is, you need multiple votes on the same post to delete it, and without users actually checking posts with pending delete votes, the posts are unlikely to gather the votes in question. There isn't a review queue for delete votes, like there is for close votes. As it is, though, our current policy basically concedes that this method doesn't work (and indeed, it doesn't work in practice). However, the problem seems relatively fixable; we merely need to inform high-reputation users of the existence of delete votes. As linked earlier (but I'll repeat the link to make it easier to find), there's a page that does this (plus another one for delete votes here on Meta); it's just that nobody but me seems to be checking it. Is there a way in which we can encourage users to check this page more often (like they seem to check the review queue)?